Partial and full agonists of A1 adenosine receptors

ABSTRACT

Disclosed are novel compounds that are partial and full A 1  adenosine receptor agonists, useful for treating various disease states, in particular the supraventricular tachycardias, emesis, angina, myocardial infarction and hyperlipidemia.

PARTIAL AND FULL AGONISTS OF A₁ ADENOSINE RECEPTORS

[0001] Priority is claimed to U.S. Provisional Patent Application SerialNo. 60/403,712, filed Aug. 15, 2002, and U.S. Provisional PatentApplication Serial No. 60/450,094, filed Feb. 25, 2003, the completedisclosures of which are hereby incorporated by reference.

FIELD OF THE INVENTION

[0002] The present invention relates to novel compounds that are partialor full A₁ adenosine receptor agonists, and to their use in treatingmammals for various disease states, including cardiovascular diseases,in particular arrhythmia and the prevention of sudden death resultingfrom arrhythmia, ischemia, and CNS disorders including pain, epilepsy,and emesis. A₁ adenosine receptor agonists are antilipolytic agents, andare useful for treating metabolic disorders, including diabetes andobesity. The invention also relates to methods for their preparation,and to pharmaceutical compositions containing such compounds.

BACKGROUND

[0003] Adenosine is a naturally occurring nucleoside, which exerts itsbiological effects by interacting with a family of adenosine receptorsknown as A₁, A_(2a), A_(2b), and A₃, all of which modulate importantphysiological processes. For example, A_(2A) adenosine receptorsmodulate coronary vasodilation, A_(2B) receptors have been implicated inmast cell activation, asthma, vasodilation, regulation of cell growth,intestinal function, and modulation of neurosecretion (See AdenosineA_(2B) Receptors as Therapeutic Targets, Drug Dev Res 45:198; Feoktistovet al.., Trends Pharmacol Sci 19:148-153), and A₃ adenosine receptorsmodulate cell proliferation processes.

[0004] A₁ adenosine receptor agonists modulates the cardiostimulatoryeffects of catecholamine (mediated via the inhibition of adenylatecyclase), and slow the heart rate (HR) and prolong impulse propagationthrough the AV node, which is due in great part to activation ofI_(KAdo). (B. Lerman and L. Belardinelli Circulation, Vol. 83 (1991), P1499-1509 and J. C. Shryock and L. Belardinelli The Am. J. Cardiology,Vol. 79 (1997) P 2-10). Stimulation of the A₁ adenosine receptorshortens the duration and decreases the amplitude of the actionpotential of AV nodal cells, and hence prolongs the refractory period ofthe AV nodal cell. Thus, stimulation of A₁ receptors provides a methodof treating supraventricular tachycardias, including termination ofnodal re-entrant tachycardias, and control of ventricular rate duringatrial fibrillation and flutter.

[0005] Elevated serum levels of non-esterified free fatty acid (NEFA)are detrimental to both the mechanical and electrical function of theheart, and A₁ adenosine receptor agonists are potent and efficaciousinhibitors of lipolysis. Importantly, because A₁ adenosine receptoragonists are more potent in adipose tissue that in heart tissues, theydecrease lipolysis at concentrations that do not affect heart rate.Thus, A₁ adenosine receptor agonists are useful for treating metabolicdisorders such as non-insulin-dependent diabetes mellitus and obesityvia their anti-lipolytic activity. The antilipolytic effect of adenosineA₁ receptor agonists is also useful in the management of congestiveheart failure. Furthermore, A₁ adenosine receptor agonists areprotective against cardioischemia. A₁ adenosine receptor agonists arealso useful as chemotherapeutics in the treatment of CNS disordersincluding epilepsy (anticonvulsant activity) and ischemia.

[0006] Accordingly, it is an object of this invention to providecompounds that are potent full A₁ adenosine receptor agonists or partialA₁ adenosine receptor agonists. Preferred compounds of the invention areselective for the A₁ adenosine receptor, which minimizes undesired sideeffects related to stimulation or antagonism of the other adenosinereceptors.

SUMMARY OF THE INVENTION

[0007] Accordingly, in a first aspect, the invention relates tocompounds of Formula I:

[0008] wherein:

[0009] R¹ is optionally substituted cycloalkyl, optionally substitutedheterocyclyl, optionally substituted aryl, or optionally substitutedheteroaryl;

[0010] R² is hydrogen, halo, trifluoromethyl, or cyano;

[0011] R³ is hydrogen, optionally substituted cycloalkyl, optionallysubstituted aryl, optionally substituted heteroaryl, or optionallysubstituted heterocyclyl,

[0012] R⁴ and R⁵ are independently hydrogen or optionally substitutedacyl;

[0013] X is a covalent bond or lower alkylene optionally substituted bycycloalkyl;

[0014] X¹ is a covalent bond or alkylene.

[0015] Y is a covalent bond or lower alkylene optionally substituted byhydroxy or cycloalkyl; and

[0016] Z is —C≡C—, —R⁶C═CR⁷—, or —CHR⁶CHR⁷—, in which R⁶ and R⁷ at eachoccurrence are hydrogen or lower alkyl

[0017] A second aspect of the invention relates to pharmaceuticalformulations, comprising a therapeutically effective amount of acompound of Formula I and at least one pharmaceutically acceptableexcipient.

[0018] A third aspect of the invention relates to a method of using thecompounds of Formula I in the treatment of a disease or condition in amammal that can be effectively treated with a partial or full selectiveA₁ adenosine receptor agonist. Such diseases and conditions include atleast one of the following; supraventricular tachycardia, includingatrial fibrillation, and atrial flutter, ischemia, including that due tostable and unstable angina, congestive heart failure, myocardialinfarction, disorders of the CNS including epilepsy and stroke,metabolic disorders, such as obesity and diabetes, or the sequela ofdiabetes or congestive heart failure specifically hyperlipidemia, whichis alleviated by the antilipolytic effect of A₁ agonists on adipocytes;and the treatment of nausea (emesis).

[0019] A fourth aspect of this invention relates to methods of preparingthe compounds of Formula I.

[0020] Of the compounds of Formula I, one preferred class includes thosecompounds in which Z is —C≡C—, particularly those compounds in which X,X¹ and Y are covalent bonds. A preferred group within this classincludes those compounds in which R¹ is optionally substitutedcycloalkyl optionally substituted heterocyclyl, or optionallysubstituted heteroaryl, and R², R⁴ and R⁵ are hydrogen.

[0021] A preferred subgroup includes those compounds of Formula I inwhich R³ is hydrogen or optionally substituted aryl, especiallyoptionally substituted phenyl. Particularly preferred compounds withinthis subgroup are those compounds in which R¹ is cycloalkyl, especiallycyclopentyl or hydroxycyclopentyl, or optionally substitutedheterocyclyl, especially tetrahydrofuran-3-yl, and R³ is hydrogen. Otherpreferred compounds within this subgroup includes those compounds ofFormula I in which R³ is optionally substituted phenyl. Particularlypreferred are those compounds in which R¹ is cycloalkyl, especiallycyclopentyl, or optionally substituted heterocyclyl, especiallytetrahydrofuran-3-yl, and R³ is 2-fluorophenyl or2-trifluoromethylphenyl.

[0022] Another preferred subgroup includes those compounds of Formula Iin which R³ is optionally substituted aryl. Particularly preferredcompounds within this subgroup are those compounds in which R¹ iscycloalkyl, especially cyclopentyl, or optionally substitutedheterocyclyl, especially tetrahydrofuran-3-yl. Preferred R³ groupsinclude optionally substituted thienyl, especially 5-chlorothien-2-yl.

[0023] Of the compounds of Formula I, another preferred class includesthose compounds in which Z is —R⁶C═CR⁷—, particularly those compounds inwhich R⁶ and R⁷ are hydrogen and X, X¹ and Y are covalent bonds. Apreferred group within this class includes those compounds in which R¹is optionally substituted cycloalkyl, and R², R⁴ and R⁵ are hydrogen. Apreferred subgroup includes those compounds of Formula I in which R³ isoptionally substituted aryl or optionally substituted heteroaryl.Particularly preferred are those compounds in which R³ includesoptionally substituted phenyl, especially phenyl or 2-methylphenyl, oroptionally substituted thienyl, especially 5-chlorothien-2-yl.

[0024] Definitions and General Parameters

[0025] As used in the present specification, the following words andphrases are generally intended to have the meanings as set forth below,except to the extent that the context in which they are used indicatesotherwise.

[0026] The term “alkyl” refers to a monoradical branched or unbranchedsaturated hydrocarbon chain having from 1 to 20 carbon atoms. This termis exemplified by groups such as methyl, ethyl, n-propyl, iso-propyl,n-butyl, iso-butyl, t-butyl, n-hexyl, n-decyl, tetradecyl, and the like.

[0027] The term “substituted alkyl” refers to:

[0028] 1) an alkyl group as defined above, having 1, 2, 3, 4 or 5substituents, for example 1 to 3 substituents, selected from the groupconsisting of alkenyl, alkynyl, alkoxy, cycloalkyl, cycloalkenyl, acyl,acylamino, acyloxy, amino, aminocarbonyl, alkoxycarbonylamino, azido,cyano, halogen, hydroxy, keto, thiocarbonyl, carboxy, carboxyalkyl,arylthio, heteroarylthio, heterocyclylthio, thiol, alkylthio, aryl,aryloxy, heteroaryl, aminosulfonyl, aminocarbonylamino, heteroaryloxy,heterocyclyl, heterocyclooxy, hydroxyamino, alkoxyamino, nitro,—SO-alkyl, —SO-aryl, —SO-heteroaryl, —SO₂-alkyl, SO₂-aryl and—SO₂-heteroaryl. Unless otherwise constrained by the definition, allsubstituents may optionally be further substituted by 1, 2, or 3substituents chosen from alkyl, carboxy, carboxyalkyl, aminocarbonyl,hydroxy, alkoxy, halogen, CF₃, amino, substituted amino, cyano, and—S(O)_(n)R, where R is alkyl, aryl, or heteroaryl and n is 0, 1 or 2; or

[0029] 2) an alkyl group as defined above that is interrupted by 1-10atoms independently chosen from oxygen, sulfur and NR_(a)—, where R_(a)is chosen from hydrogen, alkyl, cycloalkyl, alkenyl, cycloalkenyl,alkynyl, aryl, heteroaryl and heterocyclyl. All substituents may beoptionally further substituted by alkyl, alkoxy, halogen, CF₃, amino,substituted amino, cyano, or —S(O)_(n)R, in which R is alkyl, aryl, orheteroaryl and n is 0, 1 or 2; or

[0030] 3) an alkyl group as defined above that has both 1, 2, 3, 4 or 5substituents as defined above and is also interrupted by 1-10 atoms asdefined above.

[0031] The term “lower alkyl” refers to a monoradical branched orunbranched saturated hydrocarbon chain having 1, 2, 3, 4, 5, or 6 carbonatoms. This term is exemplified by groups such as methyl, ethyl,n-propyl, iso-propyl, n-butyl, iso-butyl, t-butyl, n-hexyl, and thelike.

[0032] The term “substituted lower alkyl” refers to lower alkyl asdefined above having 1 to 5 substituents, for example 1, 2, or 3substituents, as defined for substituted alkyl, or a lower alkyl groupas defined above that is interrupted by 1, 2, 3, 4, or 5 atoms asdefined for substituted alkyl, or a lower alkyl group as defined abovethat has both 1, 2, 3, 4 or 5 substituents as defined above and is alsointerrupted by 1, 2, 3, 4, or 5 atoms as defined above.

[0033] The term “alkylene” refers to a diradical of a branched orunbranched saturated hydrocarbon chain, for example having from 1 to 20carbon atoms, preferably 1-10 carbon atoms, more preferably 1, 2, 3, 4,5 or 6 carbon atoms. This term is exemplified by groups such asmethylene (—CH₂—), ethylene (—CH₂CH₂—), the propylene isomers (e.g.,—CH₂CH₂CH₂— and —CH(CH₃)CH₂—) and the like.

[0034] The term “lower alkylene” refers to a diradical of a branched orunbranched saturated hydrocarbon chain, for example having from 1, 2, 3,4, 5, or 6 carbon atoms.

[0035] The term“substituted alkylene” refers to:

[0036] (1) an alkylene group as defined above having 1, 2, 3, 4, or 5substituents selected from the group consisting of alkyl, alkenyl,alkynyl, alkoxy, cycloalkyl, cycloalkenyl, acyl, acylamino, acyloxy,amino, aminocarbonyl, alkoxycarbonylamino, azido, cyano, halogen,hydroxy, keto, thiocarbonyl, carboxy, carboxyalkyl, arylthio,heteroarylthio, heterocyclylthio, thiol, alkylthio, aryl, aryloxy,heteroaryl, aminosulfonyl, aminocarbonylamino, heteroaryloxy,heterocyclyl, heterocyclooxy, hydroxyamino, alkoxyamino, nitro,—SO-alkyl, —SO-aryl, —SO-heteroaryl, —SO2-alkyl, SO₂-aryl and—SO₂-heteroaryl. Unless otherwise constrained by the definition, allsubstituents may optionally be further substituted by 1, 2, or 3substituents chosen from alkyl, carboxy, carboxyalkyl, aminocarbonyl,hydroxy, alkoxy, halogen, CF₃, amino, substituted amino, cyano, and—S(O)_(n)R, where R is alkyl, aryl, or heteroaryl and n is 0, 1 or 2; or

[0037] (2) an alkylene group as defined above that is interrupted by1-20 atoms independently chosen from oxygen, sulfur and NR_(a)—, whereR_(a) is chosen from hydrogen, optionally substituted alkyl, cycloalkyl,cycloalkenyl, aryl, heteroaryl and heterocycyl, or groups selected fromcarbonyl, carboxyester, carboxyamide and sulfonyl; or

[0038] (3) an alkylene group as defined above that has both 1, 2, 3, 4or 5 substituents as defined above and is also interrupted by 1-20 atomsas defined above. Examples of substituted alkylenes are chloromethylene(—CH(Cl)—), aminoethylene (—CH(NH₂)CH₂—), methylaminoethylene(—CH(NHMe)CH₂—), 2-carboxypropylene isomers(—CH₂CH(CO₂H)CH₂—),ethoxyethyl (—CH₂CH₂O—CH₂CH₂—), ethylmethylaminoethyl(—CH₂CH₂N(CH₃)CH₂CH₂—),1-ethoxy-2-(2-ethoxy-ethoxy)ethane(—CH₂CH₂O—CH₂CH₂—OCH₂CH₂—OCH₂CH₂—), and the like.

[0039] The term “aralkyl” refers to an aryl group covalently linked toan alkylene group, where aryl and alkylene are defined herein.“Optionally substituted aralkyl” refers to an optionally substitutedaryl group covalently linked to an optionally substituted alkylenegroup. Such aralkyl groups are exemplified by benzyl, phenylethyl,3-(4-methoxyphenyl)propyl, and the like.

[0040] The term “alkoxy” refers to the group R—O—, where R is optionallysubstituted alkyl or optionally substituted cycloalkyl, or R is a group—Y—Z, in which Y is optionally substituted alkylene and Z is optionallysubstituted alkenyl, optionally substituted alkynyl; or optionallysubstituted cycloalkenyl, where alkyl, alkenyl, alkynyl, cycloalkyl andcycloalkenyl are as defined herein. Preferred alkoxy groups are alkyl-O—and include, by way of example, methoxy, ethoxy, n-propoxy, iso-propoxy,n-butoxy, tert-butoxy, sec-butoxy, n-pentoxy, n-hexoxy,1,2-dimethylbutoxy, and the like.

[0041] The term “alkylthio” refers to the group R—S—, where R is asdefined for alkoxy.

[0042] The term “alkenyl” refers to a monoradical of a branched orunbranched unsaturated hydrocarbon group having from 2 to 20 carbonatoms, preferably 2 to 10 carbon atoms,and even more preferably 2 to 6carbon atoms and having 1-6, preferably 1, double bond (vinyl).Preferred alkenyl groups include ethenyl or vinyl (—CH═CH₂), 1-propyleneor allyl (—CH₂CH═CH₂), isopropylene (—C(CH₃)═CH₂),bicyclo[2.2.1]heptene, and the like. In the event that alkenyl isattached to nitrogen, the double bond cannot be alpha to the nitrogen.

[0043] The term “lower alkenyl” refers to alkenyl as defined abovehaving from 2 to 6 carbon atoms.

[0044] The term “substituted alkenyl” refers to an alkenyl group asdefined above having 1, 2, 3, 4 or 5 substituents, and preferably 1, 2,or 3 substituents, selected from the group consisting of alkyl, alkenyl,alkynyl, alkoxy, cycloalkyl, cycloalkenyl, acyl, acylamino, acyloxy,amino, aminocarbonyl, alkoxycarbonylamino, azido, cyano, halogen,hydroxy, keto, thiocarbonyl, carboxy, carboxyalkyl, arylthio,heteroarylthio, heterocyclylthio, thiol, alkylthio, aryl, aryloxy,heteroaryl, aminosulfonyl, aminocarbonylamino, heteroaryloxy,heterocyclyl, heterocyclooxy, hydroxyamino, alkoxyamino, nitro,—SO-alkyl, —SO-aryl, —SO-heteroaryl, —SO₂-alkyl, SO₂-aryl and—SO₂-heteroaryl. Unless otherwise constrained by the definition, allsubstituents may optionally be further substituted by 1, 2, or 3substituents chosen from alkyl, carboxy, carboxyalkyl, aminocarbonyl,hydroxy, alkoxy, halogen, CF₃, amino, substituted amino, cyano, and—S(O)_(n)R, where R is alkyl, aryl, or heteroaryl and n is 0, 1 or 2.

[0045] The term “alkynyl” refers to a monoradical of an unsaturatedhydrocarbon having from 2 to 20 carbon atoms, preferably 2 to 10 carbonatoms and even more preferably 2 to 6 carbon atoms and having at least 1and preferably from 1-6 sites of acetylene (triple bond) unsaturation.Preferred alkynyl groups include ethynyl, (—C≡CH), propargyl (orpropynyl, —C≡CCH₃), and the like. In the event that alkynyl is attachedto nitrogen, the triple bond cannot be alpha to the nitrogen.

[0046] The term “substituted alkynyl” refers to an alkynyl group asdefined above having 1, 2, 3, 4 or 5 substituents, and preferably 1, 2,or 3 substituents, selected from the group consisting of alkyl, alkenyl,alkynyl, alkoxy, cycloalkyl, cycloalkenyl, acyl, acylamino, acyloxy,amino, aminocarbonyl, alkoxycarbonylamino, azido, cyano, halogen,hydroxy, keto, thiocarbonyl, carboxy, carboxyalkyl, arylthio,heteroarylthio, heterocyclylthio, thiol, alkylthio, aryl, aryloxy,heteroaryl, aminosulfonyl, aminocarbonylamino, heteroaryloxy,heterocyclyl, heterocyclooxy, hydroxyamino, alkoxyamino, nitro,—SO-alkyl, —SO-aryl, —SO-heteroaryl, —SO₂-alkyl, SO₂-aryl and—SO₂-heteroaryl. Unless otherwise constrained by the definition, allsubstituents may optionally be further substituted by 1, 2, or 3substituents chosen from alkyl, carboxy, carboxyalkyl, aminocarbonyl,hydroxy, alkoxy, halogen, CF₃, amino, substituted amino, cyano, and—S(O)_(n)R, where R is alkyl, aryl, or heteroaryl and n is 0, 1 or 2.

[0047] The term “aminocarbonyl” refers to the group —C(O)NRR where eachR is independently hydrogen, alkyl, cycloaklyl, aryl, heteroaryl,heterocyclyl or where both R groups are joined to form a heterocyclicgroup (e.g., morpholino). Unless otherwise constrained by thedefinition, all substituents may optionally be further substituted by 1,2, or 3 substituents chosen from alkyl, carboxy, carboxyalkyl,aminocarbonyl, hydroxy, alkoxy, halogen, CF₃, amino, substituted amino,cyano, and —S(O)_(n)R, where R is alkyl, aryl, or heteroaryl and n is 0,1 or 2.

[0048] The term “ester” or “carboxyester” refers to the group —C(O)OR,where R is alkyl, cycloalkyl, aryl, heteroaryl, or heterocyclyl, whichmay be optionally further substituted by alkyl, alkoxy, halogen, CF₃,amino, substituted amino, cyano, or —S(O)_(n)R_(a), in which R_(a) isalkyl, aryl, or heteroaryl and n is 0, 1 or 2.

[0049] The term “acylamino” refers to the group —NRC(O)R where each R isindependently hydrogen, alkyl, aryl, heteroaryl, or heterocyclyl. Allsubstituents may be optionally further substituted by alkyl, alkoxy,halogen, CF₃, amino, substituted amino, cyano, or —S(O)_(n)R, in which Ris alkyl, aryl, or heteroaryl and n is 0, 1 or 2.

[0050] The term “acyloxy” refers to the groups —O(O)C-alkyl,—(O)C-cycloalkyl, —O(O)C-aryl, —O(O)C-heteroaryl, and—O(O)C-heterocyclyl. Unless otherwise constrained by the definition, allsubstituents may optionally be further substituted by 1, 2, or 3substituents chosen from alkyl, carboxy, carboxyalkyl, aminocarbonyl,hydroxy, alkoxy, halogen, CF₃, amino, substituted amino, cyano, and—S(O)_(n)R, where R is alkyl, aryl, or heteroaryl and n is 0, 1 or 2.

[0051] The term “aryl” refers to an aromatic carbocyclic group of 6 to20 carbon atoms having a single ring (e.g., phenyl) or multiple rings(e.g., biphenyl), or multiple condensed (fused) rings (e.g., naphthyl oranthryl). Preferred aryls include phenyl, naphthyl and the like.

[0052] Unless otherwise constrained by the definition for the arylsubstituent, such aryl groups can optionally be substituted with 1, 2,3, 4 or 5 substituents, preferably 1, 2, or 3 substituents, selectedfrom the group consisting of alkyl, alkenyl, alkynyl, alkoxy,cycloalkyl, cycloalkenyl, acyl, acylamino, acyloxy, amino,aminocarbonyl, alkoxycarbonylamino, azido, cyano, halogen, hydroxy,keto, thiocarbonyl, carboxy, carboxyalkyl, arylthio, heteroarylthio,heterocyclylthio, thiol, alkylthio, aryl, aryloxy, heteroaryl,aminosulfonyl, aminocarbonylamino, heteroaryloxy, heterocyclyl,heterocyclooxy, hydroxyamino, alkoxyamino, nitro, —SO-alkyl, —SO-aryl,—SO-heteroaryl, —SO₂-alkyl, SO₂-aryl and —SO₂-heteroaryl. Unlessotherwise constrained by the definition, all substituents may optionallybe further substituted by 1, 2, or 3 substituents chosen from alkyl,carboxy, carboxyalkyl, aminocarbonyl, hydroxy, alkoxy, halogen, CF₃,amino, substituted amino, cyano, and —S(O)_(n)R, where R is alkyl, aryl,or heteroaryl and n is 0, 1 or 2.

[0053] The term “aryloxy” refers to the group aryl-O— wherein the arylgroup is as defined above, and includes optionally substituted arylgroups as also defined above. The term “arylthio” refers to the groupR—S—, where R is as defined for aryl.

[0054] The term “amino” refers to the group —NH₂.

[0055] The term “substituted amino” refers to the group —NRR where eachR is independently selected from the group consisting of hydrogen,alkyl, cycloalkyl, aryl, heteroaryl and heterocyclyl provided that bothR groups are not hydrogen, or a group —Y—Z, in which Y is optionallysubstituted alkylene and Z is alkenyl, cycloalkenyl, or alkynyl. Unlessotherwise constrained by the definition, all substituents may optionallybe further substituted by 1, 2, or 3 substituents chosen from alkyl,carboxy, carboxyalkyl, aminocarbonyl, hydroxy, alkoxy, halogen, CF₃,amino, substituted amino, cyano, and —S(O)_(n)R, where R is alkyl, aryl,or heteroaryl and n is 0, 1 or 2.

[0056] The term “carboxyalkyl” refers to the groups —C(O)O-alkyl,—C(O)O-cycloalkyl, where alkyl and cycloalkyl, are as defined herein,and may be optionally further substituted by alkyl, alkenyl, alkynyl,alkoxy, halogen, CF₃, amino, substituted amino, cyano, or —S(O)_(n)R, inwhich R is alkyl, aryl, or heteroaryl and n is 0, 1 or 2.

[0057] The term “cycloalkyl” refers to cyclic alkyl groups of from 3 to20 carbon atoms having a single cyclic ring or multiple condensed rings.Such cycloalkyl groups include, by way of example, single ringstructures such as cyclopropyl, cyclobutyl, cyclopentyl, cyclooctyl, andthe like, or multiple ring structures such as adamantanyl, andbicyclo[2.2.1]heptane, or cyclic alkyl groups to which is fused an arylgroup, for example indan, and the like.

[0058] The term “substituted cycloalkyl” refers to cycloalkyl groupshaving 1, 2, 3, 4 or 5 substituents, and preferably 1, 2, or 3substituents, selected from the group consisting of alkyl, alkenyl,alkynyl, alkoxy, cycloalkyl, cycloalkenyl, acyl, acylamino, acyloxy,amino, aminocarbonyl, alkoxycarbonylamino, azido, cyano, halogen,hydroxy, keto, thiocarbonyl, carboxy, carboxyalkyl, arylthio,heteroarylthio, heterocyclylthio, thiol, alkylthio, aryl, aryloxy,heteroaryl, aminosulfonyl, aminocarbonylamino, heteroaryloxy,heterocyclyl, heterocyclooxy, hydroxyamino, alkoxyamino, nitro,—SO-alkyl, —SO-aryl, —SO-heteroaryl, —SO₂-alkyl, SO₂-aryl and—SO₂-heteroaryl. Unless otherwise constrained by the definition, allsubstituents may optionally be further substituted by 1, 2, or 3substituents chosen from alkyl, carboxy, carboxyalkyl, aminocarbonyl,hydroxy, alkoxy, halogen, CF₃, amino, substituted amino, cyano, and—S(O)_(n)R, where R is alkyl, aryl, or heteroaryl and n is 0, 1 or 2.

[0059] The term “halogen” or “halo” refers to fluoro, bromo, chloro, andiodo.

[0060] The term “acyl” denotes a group —C(O)R, in which R is hydrogen,optionally substituted alkyl, optionally substituted cycloalkyl,optionally substituted heterocyclyl, optionally substituted aryl, andoptionally substituted heteroaryl.

[0061] The term “heteroaryl” refers to an aromatic group (i.e.,unsaturated) comprising 1 to 15 carbon atoms and 1 to 4 heteroatomsselected from oxygen, nitrogen and sulfur within at least one ring.

[0062] Unless otherwise constrained by the definition for the heteroarylsubstituent, such heteroaryl groups can be optionally substituted with 1to 5 substituents, preferably 1, 2, or 3 substituents selected from thegroup consisting of alkyl, alkenyl, alkynyl, alkoxy, cycloalkyl,cycloalkenyl, acyl, acylamino, acyloxy, amino, aminocarbonyl,alkoxycarbonylamino, azido, cyano, halogen, hydroxy, keto, thiocarbonyl,carboxy, carboxyalkyl (an alkyl ester), arylthio, heteroaryl,heteroarylthio, heterocyclylthio, thiol, alkylthio, aryl, aryloxy,aralkyl, heteroaryl, aminosulfonyl, aminocarbonylamino, heteroaryloxy,heterocyclyl, heterocyclooxy, hydroxyamino, alkoxyamino, nitro,—SO-alkyl, —SO-aryl, —SO-heteroaryl, —SO₂-alkyl, SO₂-aryl and—SO₂-heteroaryl. Unless otherwise constrained by the definition, allsubstituents may optionally be further substituted by 1, 2, or 3substituents chosen from alkyl, carboxy, carboxyalkyl, aminocarbonyl,hydroxy, alkoxy, halogen, CF₃, amino, substituted amino, cyano, and—S(O)_(n)R, where R is alkyl, aryl, or heteroaryl and n is 0, 1 or 2.Such heteroaryl groups can have a single ring (e.g., pyridyl or furyl)or multiple condensed rings (e.g., indolizinyl, benzothiazole, orbenzothienyl). Examples of nitrogen heterocycles and heteroarylsinclude, but are not limited to, pyrrole, imidazole, pyrazole, pyridine,pyrazine, pyrimidine, pyridazine, indolizine, isoindole, indole,indazole, purine, quinolizine, isoquinoline, quinoline, phthalazine,naphthylpyridine, quinoxaline, quinazoline, cinnoline, pteridine,carbazole, carboline, phenanthridine, acridine, phenanthroline,isothiazole, phenazine, isoxazole, phenoxazine, phenothiazine,imidazolidine, imidazoline, and the like as well as N-alkoxy-nitrogencontaining heteroaryl compounds.

[0063] The term “heteroaryloxy” refers to the group heteroaryl-O—.

[0064] The term “heterocyclyl” refers to a monoradical saturated orpartially unsaturated group having a single ring or multiple condensedrings, having from 1 to 40 carbon atoms and from 1 to 10 hetero atoms,preferably 1 to 4 heteroatoms, selected from nitrogen, sulfur,phosphorus, and/or oxygen within the ring.

[0065] Unless otherwise constrained by the definition for theheterocyclic substituent, such heterocyclic groups can be optionallysubstituted with 1 to 5, and preferably 1, 2, or 3 substituents,selected from the group consisting of alkyl, alkenyl, alkynyl, alkoxy,cycloalkyl, cycloalkenyl, acyl, acylamino, acyloxy, amino,aminocarbonyl, alkoxycarbonylamino, azido, cyano, halogen, hydroxy,keto, thiocarbonyl, carboxy, carboxyalkyl, arylthio, heteroarylthio,heterocyclylthio, thiol, alkylthio, aryl, aryloxy, heteroaryl,aminosulfonyl, aminocarbonylamino, heteroaryloxy, heterocyclyl,heterocyclooxy, hydroxyamino, alkoxyamino, nitro, —SO-alkyl, —SO-aryl,—SO-heteroaryl, —SO₂-alkyl, SO₂-aryl and —SO₂-heteroaryl. Unlessotherwise constrained by the definition, all substituents may optionallybe further substituted by 1, 2, or 3 substituents chosen from alkyl,carboxy, carboxyalkyl, aminocarbonyl, hydroxy, alkoxy, halogen, CF₃,amino, substituted amino, cyano, and —S(O)_(n)R, where R is alkyl, aryl,or heteroaryl and n is 0, 1 or 2. Heterocyclic groups can have a singlering or multiple condensed rings. Preferred heterocyclics includetetrahydrofuranyl, morpholino, piperidinyl, and the like.

[0066] The term “thiol” refers to the group —SH.

[0067] The term “substituted alkylthio” refers to the group—S-substituted alkyl.

[0068] The term “heteroarylthiol” refers to the group —S-heteroarylwherein the heteroaryl group is as defined above including optionallysubstituted heteroaryl groups as also defined above.

[0069] The term “sulfoxide” refers to a group —S(O)R, in which R isalkyl, aryl, or heteroaryl. “Substituted sulfoxide” refers to a group—S(O)R, in which R is substituted alkyl, substituted aryl, orsubstituted heteroaryl, as defined herein.

[0070] The term “sulfone” refers to a group —S(O)₂R, in which R isalkyl, aryl, or heteroaryl. “Substituted sulfone” refers to a group—S(O)₂R, in which R is substituted alkyl, substituted aryl, orsubstituted heteroaryl, as defined herein.

[0071] The term “keto” refers to a group —C(O)—. The term “thiocarbonyl”refers to a group —C(S)—. The term “carboxy” refers to a group —C(O)—OH.

[0072] “Optional” or “optionally” means that the subsequently describedevent or circumstance may or may not occur, and that the descriptionincludes instances where said event or circumstance occurs and instancesin which it does not.

[0073] The term “compound of Formula I” is intended to encompass thecompounds of the invention as disclosed and polymorphs thereof,pharmaceutically acceptable salts, pharmaceutically acceptable esters,and prodrugs of such compounds. Additionally, the compounds of theinvention may possess one or more asymmetric centers, and can beproduced as a racemic mixture or as individual enantiomers ordiastereoisomers. The number of stereoisomers present in any givencompound of Formula I depends upon the number of asymmetric centerspresent (there are 2^(n) stereoisomers possible where n is the number ofasymmetric centers). The individual stereoisomers may be obtained byresolving a racemic or non-racemic mixture of an intermediate at someappropriate stage of the synthesis, or by resolution of the compound ofFormula I by conventional means. The individual stereoisomers (includingindividual enantiomers and diastereoisomers) as well as racemic andnon-racemic mixtures of stereoisomers are encompassed within the scopeof the present invention, all of which are intended to be depicted bythe structures of this specification unless otherwise specificallyindicated.

[0074] “Isomers” are different compounds that have the same molecularformula.

[0075] “Stereoisomers” are isomers that differ only in the way the atomsare arranged in space.

[0076] “Enantiomers” are a pair of stereoisomers that arenon-superimposable mirror images of each other. A 1:1 mixture of a pairof enantiomers is a “racemic” mixture. The term “(±)” is used todesignate a racemic mixture where appropriate.

[0077] “Diastereoisomers” are stereoisomers that have at least twoasymmetric atoms, but which are not mirror-images of each other.

[0078] The absolute stereochemistry is specified according to theCahn-Ingold-Prelog R-S system. When the compound is a pure enantiomerthe stereochemistry at each chiral carbon may be specified by either Ror S. Resolved compounds whose absolute configuration is unknown aredesignated (+) or (−) depending on the direction (dextro- orlaevorotary) which they rotate the plane of polarized light at thewavelength of the sodium D line.

[0079] The term “therapeutically effective amount” refers to that amountof a compound of Formula I that is sufficient to effect treatment, asdefined below, when administered to a mammal in need of such treatment.The therapeutically effective amount will vary depending upon thesubject and disease condition being treated, the weight and age of thesubject, the severity of the disease condition, the manner ofadministration and the like, which can readily be determined by one ofordinary skill in the art.

[0080] The term “treatment” or “treating” means any treatment of adisease in a mammal, including:

[0081] (i) preventing the disease, that is, causing the clinicalsymptoms of the disease not to develop;

[0082] (ii) inhibiting the disease, that is, arresting the developmentof clinical symptoms; and/or

[0083] (iii) relieving the disease, that is, causing the regression ofclinical symptoms.

[0084] In many cases, the compounds of this invention are capable offorming acid and/or base salts by virtue of the presence of amino and/orcarboxyl groups or groups similar thereto. The term “pharmaceuticallyacceptable salt” refers to salts that retain the biologicaleffectiveness and properties of the compounds of Formula I, and whichare not biologically or otherwise undesirable. Pharmaceuticallyacceptable base addition salts can be prepared from inorganic andorganic bases. Salts derived from inorganic bases, include by way ofexample only, sodium, potassium, lithium, ammonium, calcium andmagnesium salts. Salts derived from organic bases include, but are notlimited to, salts of primary, secondary and tertiary amines, such asalkyl amines, dialkyl amines, trialkyl amines, substituted alkyl amines,di(substituted alkyl) amines, tri(substituted alkyl) amines, alkenylamines, dialkenyl amines, trialkenyl amines, substituted alkenyl amines,di(substituted alkenyl) amines, tri(substituted alkenyl) amines,cycloalkyl amines, di(cycloalkyl) amines, tri(cycloalkyl) amines,substituted cycloalkyl amines, disubstituted cycloalkyl amine,trisubstituted cycloalkyl amines, cycloalkenyl amines, di(cycloalkenyl)amines, tri(cycloalkenyl) amines, substituted cycloalkenyl amines,disubstituted cycloalkenyl amine, trisubstituted cycloalkenyl amines,aryl amines, diaryl amines, triaryl amines, heteroaryl amines,diheteroaryl amines, triheteroaryl amines, heterocyclic amines,diheterocyclic amines, triheterocyclic amines, mixed di- and tri-amineswhere at least two of the substituents on the amine are different andare selected from the group consisting of alkyl, substituted alkyl,alkenyl, substituted alkenyl, cycloalkyl, substituted cycloalkyl,cycloalkenyl, substituted cycloalkenyl, aryl, heteroaryl, heterocyclic,and the like. Also included are amines where the two or threesubstituents, together with the amino nitrogen, form a heterocyclic orheteroaryl group.

[0085] Specific examples of suitable amines include, by way of exampleonly, isopropylamine, trimethyl amine, diethyl amine, tri(iso-propyl)amine, tri(n-propyl) amine, ethanolamine, 2-dimethylaminoethanol,tromethamine, lysine, arginine, histidine, caffeine, procaine,hydrabamine, choline, betaine, ethylenediamine, glucosamine,N-alkylglucamines, theobromine, purines, piperazine, piperidine,morpholine, N-ethylpiperidine, and the like.

[0086] Pharmaceutically acceptable acid addition salts may be preparedfrom inorganic and organic acids. Salts derived from inorganic acidsinclude hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid,phosphoric acid, and the like. Salts derived from organic acids includeacetic acid, propionic acid, glycolic acid, pyruvic acid, oxalic acid,malic acid, malonic acid, succinic acid, maleic acid, fumaric acid,tartaric acid, citric acid, benzoic acid, cinnarnic acid, mandelic acid,methanesulfonic acid, ethanesulfonic acid, p-toluene-sulfonic acid,salicylic acid, and the like.

[0087] As used herein, “pharmaceutically acceptable carrier” includesany and all solvents, dispersion media, coatings, antibacterial andantifungal agents, isotonic and absorption delaying agents and the like.The use of such media and agents for pharmaceutically active substancesis well known in the art. Except insofar as any conventional media oragent is incompatible with the active ingredient, its use in thetherapeutic compositions is contemplated. Supplementary activeingredients can also be incorporated into the compositions.

[0088] As used herein, the term “agonist” refers to the ability of acompound to interact with a receptor and evoke a maximal physiologicaleffect (that is, activate or stimulate the receptor). This effect isknown as the intrinsic efficacy. Many full agonists of the adenosine A₁receptor are known to those skilled in the art, for exampleN⁶-cyclopentyladenosine (CPA, or CCPA). Some adenosine A₁ agonists arereferred to as “partial agonists” because they interact with adenosineA₁ receptors but produce a less than maximal response when compared toan agonist such as CPA.

[0089] The intrinsic efficacy of a compound is its differential effecton a selected tissue. Thus, a compound may be a full agonist in a giventissue but a partial in others. The compounds identified by thisinvention have therapeutically useful affinities for the adenosine A₁receptor but have a range of intrinsic efficacies from full agonist topartial agonist. That is, some compounds may have no effect with respectto a given effector system in a given cell type, but be a full agonistin another cell type and/or effector system. A partial agonist targetedto a selected target is likely to cause fewer side effects than a fullagonist, because they will be less likely to induce desensitization ofthe A₁ receptor (R. B. Clark, B. J. Knoll, R. Barber TiPS, Vol. 20(1999) p. 279-286) and to cause side effects. Chronic administration ofa full agonist (R-N6-phenylisopropyladenosine, R-PIA) for 7 days led toa desensitization of the A₁ receptor in terms of the dromotropicresponse in guinea pigs (note: a decrease in receptor number wasobserved—D. M. Dennis, J. C. Shryock, L. Belardinelli JPET, Vol. 272(1995) p. 1024-1035). The A₁ agonist induced inhibitory effect on theproduction of cAMP by adenylate cyclase in adipocytes has been shown todesensitize upon chronic treatment with an A₁ agonist as well (W. J.Parsons and G. L. J. Biol. Chem. Vol. 262 (1987) p. 841-847).

[0090] Nomenclature

[0091] The naming and numbering of the compounds of the invention isillustrated with a representative compound of Formula I in which R¹ iscyclopentyl, R² is hydrogen, R³ is 2-fluorophenyl, R⁴ and R⁵ are bothhydrogen, X, X,¹ and Y are covalent bonds, and Z is —C═C—:

[0092] which is named:(4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]-5-[2-(2-fluorophenyl)ethynyl]oxolane-3,4-diol,or alternatively may be named:(4S,2R,3R,5R)-2-[6-(cyclopentylamino)-9H-purin-9-yl]-5-[2-(2-fluorophenyl)ethynyl]tetrahydrofran-3,4-diol.

[0093] Synthetic Reaction Parameters

[0094] The terms “solvent”, “inert organic solvent” or “inert solvent”mean a solvent inert under the conditions of the reaction beingdescribed in conjunction therewith [including, for example, benzene,toluene, acetonitrile, tetrahydrofuran (“THF”), dimethylformamide(“DMF”), chloroform, methylene chloride (or dichloromethane), diethylether, methanol, pyridine and the like]. Unless specified to thecontrary, the solvents used in the reactions of the present inventionare inert organic solvents.

[0095] The term “q.s.” means adding a quantity sufficient to achieve astated function, e.g., to bring a solution to the desired volume (i.e.,100%).

Synthesis of the Compounds of Formula I

[0096] The compounds of Formula I where R³ is hydrogen, X¹ and Y arecovalent bonds, and Z is —C═C— are prepared starting from a compound offormula (1) as shown in Reaction Scheme I.

[0097] Step 1—Preparation of Formula (2)

[0098] The starting compounds of formula (1) are commercially available(for example, the compound of formula (1) in which R² is hydrogen isavailable from Aldrich, Milwaukee), or are prepared by means well knownto those in the art. The compound of formula (2) is preparedconventionally from the compound of formula (1) by reaction with2,2-dimethoxypropane in an inert solvent, preferablyN,N-dimethylformamide, in the presence of a catalytic amount of an acidcatalyst, preferably p-toluenesulfonic acid, at a temperature of about40-90° C., preferably about 70° C., for about 24-72 hours, preferablyabout 48 hours. When the reaction is substantially complete, the productof formula (2) is isolated by conventional means, for example removal ofthe solvent under reduced pressure and purifying the residue bychromatography.

[0099] Step 2—Preparation of Formula (3)

[0100] The 6-chloro moiety is displaced from the compound of formula (2)by reaction with a compound of formula R¹XNH₂, where X is as definedabove, in the presence of a base, for example triethylamine. Thereaction is carried out in an inert protic solvent, for example ethanol,at a temperature of about reflux, for about 14-48 hours, preferablyabout 16 hours. When the reaction is substantially complete, the productof formula (3) is isolated by conventional means, for example by removalof the solvent under reduced pressure, followed by crystallization ofthe residue from a suitable solvent.

[0101] It should be noted that steps 1 and 2 may be carried out inreverse order.

[0102] Step 3—Preparation of Formula (4)

[0103] The hydroxymethyl compound of formula (3) is oxidized to analdehyde of formula (4) using a modification of the Moffat Oxidation. Ingeneral, to the compound of formula (3) is added a mixture of1,3-dicyclohexylcarbodimide DCC, dimethysulfoxide and pyridine. Theinitial reaction is carried out at a temperature of about −5° to about10° C., preferably about 0° C., and then at about room temperature forabout 6-48 hours, preferably about 18 hours. When the reaction issubstantially complete, the aldehyde of formula (4) is isolated byconventional means, for example by partitioning the product betweenethyl acetate and water and removing the solvent under reduced pressure.The product is used in the next step without further purification.

[0104] Step 4—Preparation of Formula (5).

[0105] The 4′-aldehyde group is converted to an ethynyl group byreaction with bromomethyltriphenylphosphonium bromide in the presence ofa strong base, preferably potassium t-butoxide. The reaction is carriedout in an inert solvent, preferably tetrahydrofuran, at a temperature ofabout −80° C., allowing the reaction mixture to gradually warm to roomtemperature over a period of about 1-3 days. When the reaction issubstantially complete, the product of formula (5) is isolated byconventional means, for example by removal of the solvent under reducedpressure, followed by partition between a solvent such as ethyl acetateand water, removing the solvent under reduced pressure. The residue maythen be further purified by chromatography on silica gel to provide the5′-ethynyl compound of formula (5).

[0106] Step 5—Preparation of Formula I

[0107] The acetonide-protected compound of formula (5) is then convertedinto a compound of Formula I in which Y is a covalent bond, Z is —C═C—,and R³ is hydrogen by treatment with an acid, for example an organicacid, for example acetic acid. The reaction is carried out in a mixtureof the acid and water, at about 50-100° C., preferably about 80-90° C.,for about 10-48 hours, preferably about 16 hours. When the reaction issubstantially complete, the product of Formula I is isolated byconventional means, for example by removal of the solvent under reducedpressure, followed by chromatography of the residue on silica gel.

[0108] Alternative Preparation of a Compound of Formula I

[0109] The compounds of Formula I where R³ is hydrogen, X¹ and Y arecovalent bonds, and Z is —C═C— may alternatively be prepared startingfrom a compound of formula (1) as shown in Reaction Scheme IA. Thismethod of synthesis is preferred when there is substitution on the R¹moiety, for example a hydroxy substituent.

[0110] Step 1 is carried out as shown in Reaction Scheme I.

[0111] Step 2—Preparation of Formula (4a)

[0112] The hydroxymethyl compound of formula (2) is oxidized to analdehyde of formula (4a) using a modification of the Moffat Oxidation.In general, to the compound of formula (2) is added a mixture of DCC,dimethysulfoxide and pyridine. The initial reaction is carried out at atemperature of about −5° to about 10° C., preferably about 0° C., andthen at about room temperature for about 6-48 hours, preferably about 18hours. When the reaction is substantially complete, the aldehyde offormula (4a) is isolated by conventional means, for example bypartitioning the product between ethyl acetate and water and removingthe solvent under reduced pressure. The product is used in the next stepwithout further purification.

[0113] Step 3—Preparation of Formula (5a)

[0114] The 5′-aldehyde group is converted to an ethynyl group byreaction with bromomethyltriphenylphosphonium bromide in the presence ofa strong base, preferably potassium t-butoxide. The reaction is carriedout in an inert solvent, preferably tetrahydrofuran, at a temperature ofabout −80° C., allowing the reaction mixture to gradually warm to roomtemperature over a period of about 1-3 days. When the reaction issubstantially complete, the product of formula (5a) is isolated byconventional means.

[0115] Step 4—Preparation of Formula (5)

[0116] The 6-chloro moiety is displaced from the compound of formula(5a) by reaction with a compound of formula R¹XNH₂, where X is asdefined above, in the presence of a base, for example triethylamine. Thereaction is carried out in an inert protic solvent, for example ethanol,at a temperature of about reflux, for about 14-48 hours, preferablyabout 16 hours. When the reaction is substantially complete, the productof Formula (5) is isolated by conventional means.

[0117] Step 5—Preparation of Formula I

[0118] The compound of formula (5) is then converted to a compound ofFormula I as shown in Reaction Scheme I above.

[0119] Preparation of a Compound of Formula I in which R³ is notHydrogen

[0120] The preparation of a compound of Formula I in which R³ is nothydrogen, X¹ is a covalent bond, Y is as defined above, and Z is —C≡C—is shown in Reaction Scheme II.

[0121] Step 1—Preparation of Formula (6)

[0122] The 4′-ethynyl compound of formula (5) is converted to a compoundof formula (6) by reaction with a compound of the formula R³Y—LG, inwhich LG is a leaving group, preferably a halogen, for example iodo orbromo. The reaction is carried out in the presence of catalytic amountsof dichlorobis(triphenylphosphine)palladium(II) and copper(II)iodideplus a tertiary amine, for example triethylamine, in an inert solvent,for example tetrahydrofuran, at a temperature of about room temperaturefor about 15 minutes. When the reaction is substantially complete, theproduct of Formula I is isolated by conventional means, for example byremoval of the solvent under reduced pressure, followed by preparativechromatography on silica gel to provide the 5′-substituted ethynylcompound of Formula I.

[0123] Step 2—Preparation of Formula I

[0124] The compound of formula (6) is then deprotected in the samemanner as shown above in Reaction Scheme 1 by treatment with an acid,preferably an organic acid, for example acetic acid, to provide acompound of Formula I.

[0125] Alternative Preparation of a Compound of Formula I in which R³ isnot Hydrogen

[0126] Alternatively, a compound of Formula I in which R³ is nothydrogen, X¹ is a covalent bond, Y is as defined above, and Z is —C≡C—may be prepared directly from a compound of Formula I in which R³ ishydrogen as shown in Reaction Scheme IIA.

[0127] Step 1

[0128] The 4′-ethynyl compound of Formula I is converted to a compoundof Formula I in which R³ is not hydrogen by reaction with a compound ofthe formula R³Y—LG, in which LG is a leaving group, preferably ahalogen, for example iodo or bromo. The reaction is carried out in thepresence of catalytic amounts ofdichlorobis(triphenylphosphine)palladium(II) and copper(I)iodide plus atertiary amine, for example triethylamine, in an inert solvent, forexample tetrahydrofuran, at a temperature of about room temperature forabout 15 minutes. When the reaction is substantially complete, theproduct of Formula I in which R³ is not hydrogen is isolated byconventional means, for example by removal of the solvent under reducedpressure, followed by preparative chromatography on silica gel toprovide the 4′-substituted ethynyl compound of Formula I.

[0129] Preparation of a Compound of Formula I in which Z is —CH═CH—

[0130] The preparation of a compound of Formula I in which X¹ is acovalent bond and Z is —CH═CH— is shown in Reaction Scheme III.

[0131] Step 1—Preparation of Formula (7)

[0132] The 4′-aldehyde group is converted to an ethenyl group using theWittig reaction, by reaction of a compound of formula (4), thepreparation of which was shown above, with R³Y—CH₂P(Ph)₃Br (where Ph isphenyl), in the presence of a base, for example aqueoussodium-hydroxide. The reaction is carried out in an inert solvent, forexample dichloromethane, at a temperature of about room temperature,over a period of about 1-10 hours. When the reaction is substantiallycomplete, the product of formula (7) is isolated by conventional means,for example by removal of the solvent under reduced pressure, followedby partition between a solvent such as ethyl acetate and water, removingthe solvent under reduced pressure. The residue may be further purifiedby chromatography on silica gel to provide the 4′-ethenyl compound offormula (7).

[0133] Step 2—Preparation of a Compound of Formula I in which Z is—CH═CH—

[0134] The compound of formula (7) is then deprotected in the samemanner as shown above in Reaction Scheme 1 by treatment with an acid,for example an organic acid, for example acetic acid, to provide acompound of Formula I.

[0135] Preparation of a Compound of Formula I in which Z is —CH₂CH₂—

[0136] The preparation of a compound of Formula I in which X¹ is acovalent bond and Z is —CH₂CH₂— is shown in Reaction Scheme IV.

[0137] A compound of Formula I in which Z is —CH₂CH₂- is prepared from acompound of Formula I in which Z is —CH=CH— (or, alternatively, acompound of Formula I in which Z is —C≡C— may be used). In general, thecompound of Formula I in which Z is —CH═CH— is dissolved in an inertsolvent and stirred with a catalyst, for example palladium hydroxide,and a catalytic hydrogenation transfer reagent, such as cyclohexene. Thereaction is carried out in an inert solvent, for example ethanol, atabout room temperature, over a period of about 10-48 hours. When thereaction is substantially complete, the product of Formula I is isolatedby conventional means, for example by removal of the solvent underreduced pressure, followed by chromatography, to provide a compound ofFormula I in which Z is —CH₂CH₂—.

[0138] B. Preparation of Formula I where R² is Hydrogen and X¹ is CH₂.

[0139] The compounds of Formula I where R³ is hydrogen, Y is a covalentbond, X¹ is CH₂, and Z is —C≡C— may be prepared starting from a compoundof formula (4), as shown in Reaction Scheme V.

[0140] Step 1—Preparation of Formula (8)

[0141] N-sodium hexamethyldisilazane is reacted withbenzyloxymethyltriphenylphosphonium chloride (formula 4a) at atemperature of about −80° C., for about 1 hour. The compound of formula(4), prepared as shown in Reaction Scheme 1, or by means well known tothose in the art, is dissolved in an inert solvent, for exampletetrahydrofuran, and added to the reaction mixture, which is allowed torise to about room temperature, and stirred from 4-24 hours preferably 8hours. When the reaction is substantially complete, the product isisolated and purified conventionally, for example by crystallization ofthe residue.

[0142] Step 2a. Preparation of Formula (9)

[0143] The compound of formula (9) is prepared conventionally from thecompound of formula (8) by hydrogenation in the presence of with acatalyst, for example Pd/C. When the reaction is substantially complete,the product of formula (9) is isolated by conventional means and usedwithout further purification.

[0144] Step 2b. Preparation of Formula (10)

[0145] The compound of formula (9) is deprotected by hydrogenation inthe presence of a catalyst, for example palladium hydroxide, and acatalytic hydrogenation transfer reagent, such as cyclohexene. Thereaction is carried out in an inert solvent, for example ethanol, atabout room temperature, over a period of about 2-7 days, preferably 5days, at about 75-100° C., preferably about 80° C. When the reaction issubstantially complete, the product of formula (10) is isolated byconventional means, for example by removal of the solvent by filtration,followed by purification by chromatography on silica gel, to provide thecompound of formula (10).

[0146] Step 3.—Preparation of Formula (11)

[0147] The hydroxymethyl compound of formula (10) is oxidized to analdehyde of formula (11) using a modification of the Moffat Oxidation.In general, the compound of formula (10) is reacted with a mixture ofdicyclohexylcarbodiimide, dimethylsulfoxide and pyridine. The initialreaction is carried out at a temperature of about −5°-10° C., preferablyabout 0° C., and then at about room temperature for about 6-48 hours,preferably about 18 hours. When the reaction is substantially complete,the aldehyde of formula (11) is isolated by conventional means. Theproduct is for example used in the next step without furtherpurification.

[0148] Step 4—Preparation of Formula (12)

[0149] The 4′-aldehyde group is converted to an ethynyl group byreaction with bromomethyltriphenylphosphonium bromide in the presence ofa strong base, for example potassium t-butoxide. The reaction is carriedout in an inert solvent, for example tetrahydrofuran, at a temperatureof about −80° C., allowing the reaction mixture to gradually warm toroom temperature, and stirring for about 1-3 days. When the reaction issubstantially complete, the product of formula (12) is isolated andpurified by conventional means, for example by chromatography on silicagel, to provide the 5′-ethynyl compound of formula (12).

[0150] Step 5—Preparation of Formula I

[0151] The acetonide-protected compound of formula (12) is thenconverted into a compound of Formula I in which Y is a covalent bond, Zis —C≡C—, and R³ is hydrogen by treatment with an acid, for exampleacetic acid. The reaction is carried out in a mixture of the acid andwater, at about 50-100° C., preferably about 80-90° C., for about 10-48hours, preferably about 16 hours. When the reaction is substantiallycomplete, the product of Formula I is isolated and purified byconventional means, for example by chromatography of the residue onsilica gel.

[0152] Preparation of Compounds of Formula I where X¹ is (CH₂)₂.

[0153] Compounds of Formula (I) where X¹ is (CH₂)₂ are obtained as shownin Reaction Scheme V but replacing the compound of Formula (4a) with acompound of Formula (4b).

[0154] Synthesis of Compounds (4a) and (4b)

[0155] Chloro(phenylmethoxy)ethane and triphenylphosphine are reacted inan inert solvent, for example benzene, and maintained under refluxconditions overnight. When the reaction is substantially complete, theproduct of formula (4a) is isolated conventionally.

[0156] Similarly, by replacing chloro(phenylmethoxy) methane withchloro(phenylmethoxy) ethane, a compound of formula (4b) is prepared.

[0157] Compounds of Formula I where X¹ is (CH₂)₂ and R³ is hydrogen areconverted to compounds of Formula I where X¹ is (CH₂)₂ and R³ is otherthan hydrogen as shown in Reaction Scheme II above.

Utility, Testing and Administration

[0158] General Utility

[0159] The compounds of Formula I are effective in the treatment ofconditions known to respond to administration of a partial or fullagonist of an A₁ adenosine receptor. Such conditions include, but arenot limited to, acute and chronic disorders of heart rhythm, especiallythose diseases characterized by rapid heart rate, in which the rate isdriven by abnormalities in the sinoatrial, atria, and AV nodal tissues.Such disorders include, but are not limited to, atrial fibrillation,supraventricular tachycardia and atrial flutter, congestive heartfailure and sudden death resulting from arrythmia, non-insulin-dependentdiabetes mellitus, hyperglycemia, epilepsy (anticonvulsant activity),and cardio-and neuro- protection.

[0160] A₁ agonists, as a result of their inhibitory action on cyclic AMPgeneration, have antilipolytic effects in adipocytes that lead to adecreased release of nonesterified fatty acids (NEFA) (E. A. van Schaicket al J. Pharmacokinetics and Biopharmaceutics, Vol. 25 (1997) p 673-694and P. Strong Clinical Science Vol. 84 (1993) p. 663-669).Non-insulin-dependent diabetes mellitus (NIDDM) is characterized by aninsulin resistance that results in hyperglycemia. Factors contributingto the observed hyperglycemia are a lack of normal glucose uptake andactivation of skeletal muscle glycogen synthase (GS). Elevated levels ofNEFA have been shown to inhibit insulin-stimulated glucose uptake andglycogen synthesis (D. Thiebaud et al Metab. Clin. Exp. Vol. 31 (1982) p1128-1136 and G. Boden et al J. Clin. Invest. Vol. 93 (1994) p2438-2446). The hypothesis of a glucose fatty acid cycle was proposed byP. J. Randle as early as 1963 (P. J. Randle et al Lancet (1963) p.785-789). Thus, limiting the supply of fatty acids to the peripheraltissues promotes carbohydrate utilization (P. Strong et al ClinicalScience Vol. 84 (1993) p. 663-669).

[0161] The benefit of an A₁ agonist in central nervous disorders hasbeen reviewed (L. J. S. Knutsen and T. F. Murray In PurinergicApproaches in Experimental Therapeutics, Eds. K. A. Jacobson and M. F.Jarvis (1997) Wiley-Liss, N.Y., P -423-470). Briefly, based onexperimental models of epilepsy, a mixed A_(2A): A₁ agonist, metrifudil,has been shown to be a potent anticonvulsant against seizures induced bythe inverse benzodiazepine agonist methyl6,7-dimethoxy-4-ethyl-beta-carboline-3-carboxylate (DMCM, H. KlitgaardEur. J. Pharmacol. (1993) Vol. 224 p. 221-228). In other studies usingCGS 21680, an A_(2A) agonist, it was concluded that the anticonvulsantactivity was attributed to activation of the A₁ receptor (G. Zhang etal. Eur. J. Pharmacol. Vol. 255 (1994) p. 239-243). Furthermore, A₁adenosine selective agonists have been shown to have anticonvulsantactivity in the DMCM model (L. J. S. Knutsen In Adenosine and AdenneNucleotides: From Molecular Biology to Integrative Physiology; eds. L.Belardinelli and A. Pelleg, Kluwer: Boston, 1995, pp 479-487). A secondarea where an A₁ adenosine agonist has a benefit is in animal models offorebrain ishemia as demonstrated by Knutsen et al (J. Med. Chem. Vol.42 (1999) p. 3463-3477). The benefit in neuroprotection is believed tobe in part due to the inhibition of the release of excitatory aminoacids (ibid).

[0162] Testing

[0163] Activity testing is conducted as described in those patents andliterature citations referenced above, and in the Examples below, and bymethods apparent to one skilled in the art.

[0164] Pharmaceutical Compositions

[0165] The compounds of Formula I are usually administered in the formof pharmaceutical compositions. This invention therefore providespharmaceutical compositions that contain, as the active ingredient, oneor more of the compounds of Formula I, or a pharmaceutically acceptablesalt or ester thereof, and one or more pharmaceutically acceptableexcipients, carriers, including inert solid diluents and fillers,diluents, including sterile aqueous solution and various organicsolvents, permeation enhancers, solubilizers and adjuvants. Thecompounds of Formula I may be administered alone or in combination withother therapeutic agents. Such compositions are prepared in a mannerwell known in the pharmaceutical art (see, e.g., Remington'sPharmaceutical Sciences, Mace Publishing Co., Philadelphia, Pa. ₁₇th Ed.(1985) and “Modem Pharmaceutics”, Marcel Dekker, Inc. 3^(rd) Ed. (G. S.Banker & C. T. Rhodes, Eds.).

[0166] Administration

[0167] The compounds of Formula I may be administered in either singleor multiple doses by any of the accepted modes of administration ofagents having similar utilities, for example as described in thosepatents and patent applications incorporated by reference, includingrectal, buccal, intranasal and transdermal routes, by intra-arterialinjection, intravenously, intraperitoneally, parenterally,intramuscularly, subcutaneously, orally, topically, as an inhalant, orvia an impregnated or coated device such as a stent, for example, or anartery-inserted cylindrical polymer.

[0168] One mode for administration is parental, particularly byinjection. The forms in which the novel compositions of the presentinvention may be incorporated for administration by injection includeaqueous or oil suspensions, or emulsions, with sesame oil, corn oil,cottonseed oil, or peanut oil, as well as elixirs, mannitol, dextrose,or a sterile aqueous solution, and similar pharmaceutical vehicles.Aqueous solutions in saline are also conventionally used for injection,but less preferred in the context of the present invention. Ethanol,glycerol, propylene glycol, liquid polyethylene glycol, and the like(and suitable mixtures thereof), cyclodextrin derivatives, and vegetableoils may also be employed. The proper fluidity can be maintained, forexample, by the use of a coating, such as lecithin, by the maintenanceof the required particle size in the case of dispersion and by the useof surfactants. The prevention of the action of microorganisms can bebrought about by various antibacterial and antifungal agents, forexample, parabens, chlorobutanol, phenol, sorbic acid, thimerosal, andthe like.

[0169] Sterile injectable solutions are prepared by incorporating thecompound of Formula I in the required amount in the appropriate solventwith various other ingredients as enumerated above, as required,followed by filtered sterilization. Generally, dispersions are preparedby incorporating the various sterilized active ingredients into asterile vehicle which contains the basic dispersion medium and therequired other ingredients from those enumerated above. In the case ofsterile powders for the preparation of sterile injectable solutions, thepreferred methods of preparation are vacuum-drying and freeze-dryingtechniques which yield a powder of the active ingredient plus anyadditional desired ingredient from a previously sterile-filteredsolution thereof.

[0170] Oral administration is another route for administration of thecompounds of Formula I. Administration may be via capsule or entericcoated tablets, or the like. In making the pharmaceutical compositionsthat include at least one compound of Formula I, the active ingredientis usually diluted by an excipient and/or enclosed within such a carrierthat can be in the form of a capsule, sachet, paper or other container.When the excipient serves as a diluent, in can be a solid, semi-solid,or liquid material (as above), which acts as a vehicle, carrier ormedium for the active ingredient. Thus, the compositions can be in theform of tablets, pills, powders, lozenges, sachets, cachets, elixirs,suspensions, emulsions, solutions, syrups, aerosols (as a solid or in aliquid medium), ointments containing, for example, up to 10% by weightof the active compound, soft and hard gelatin capsules, sterileinjectable solutions, and sterile packaged powders.

[0171] Some examples of suitable excipients include lactose, dextrose,sucrose, sorbitol, mannitol, starches, gum acacia, calcium phosphate,alginates, tragacanth, gelatin, calcium silicate, microcrystallinecellulose, polyvinylpyrrolidone, cellulose, sterile water, syrup, andmethyl cellulose. The formulations can additionally include: lubricatingagents such as talc, magnesium stearate, and mineral oil; wettingagents; emulsifying and suspending agents; preserving agents such asmethyl- and propylhydroxy-benzoates; sweetening agents; and flavoringagents.

[0172] The compositions of the invention can be formulated so as toprovide quick, sustained or delayed release of the active ingredientafter administration to the patient by employing procedures known in theart. Controlled release drug delivery systems for oral administrationinclude osmotic pump systems and dissolutional systems containingpolymer-coated reservoirs or drug-polymer matrix formulations. Examplesof controlled release systems are given in U.S. Pat. Nos. 3,845,770;4,326,525; 4,902,514; and 5,616,345. Another formulation for use in themethods of the present invention employs transdermal delivery devices(“patches”). Such transdermal patches may be used to provide continuousor discontinuous infusion of the compounds of the present invention incontrolled amounts. The construction and use of transdermal patches forthe delivery of pharmaceutical agents is well known in the art. See,e.g., U.S. Pat. Nos. 5,023,252, 4,992,445 and 5,001,139. Such patchesmay be constructed for continuous, pulsatile, or on demand delivery ofpharmaceutical agents.

[0173] The compositions are formulated in a unit dosage form. The term“unit dosage forms” refers to physically discrete units suitable asunitary dosages for human subjects and other mammals, each unitcontaining a predetermined quantity of active material calculated toproduce the desired therapeutic effect, in association with a suitablepharmaceutical excipient (e.g., a tablet, capsule, ampoule). Thecompounds of Formula I are effective over a wide dosage range and isgenerally administered in a pharmaceutically effective amount. Forexample, for oral administration, each dosage unit contains from 10 mgto 2 g of a compound of Formula I, more preferably from 10 to 700 mg,and for parenteral administration, preferably from 10 to 700 mg of acompound of Formula I, more preferably about 50-200 mg. It will beunderstood, however, that the amount of the compound of Formula Iactually administered will be determined by a physician, in the light ofthe relevant circumstances, including the condition to be treated, thechosen route of administration, the actual compound administered and itsrelative activity, the age, weight, and response of the individualpatient, the severity of the patient's symptoms, and the like.

[0174] For preparing solid compositions such as tablets, the principalactive ingredient is mixed with a pharmaceutical excipient to form asolid preformulation composition containing a homogeneous mixture of acompound of the present invention. When referring to thesepreformulation compositions as homogeneous, it is meant that the activeingredient is dispersed evenly throughout the composition so that thecomposition may be readily subdivided into equally effective unit dosageforms such as tablets, pills and capsules.

[0175] The tablets or pills of the present invention may be coated orotherwise compounded to provide a dosage form affording the advantage ofprolonged action, or to protect from the acid conditions of the stomach.For example, the tablet or pill can comprise an inner dosage and anouter dosage component, the latter being in the form of an envelope overthe former. The two components can be separated by an enteric layer thatserves to resist disintegration in the stomach and permit the innercomponent to pass intact into the duodenum or to be delayed in release.A variety of materials can be used for such enteric layers or coatings,such materials including a number of polymeric acids and mixtures ofpolymeric acids with such materials as shellac, cetyl alcohol, andcellulose acetate.

[0176] Compositions for inhalation or insufflation include solutions andsuspensions in pharmaceutically acceptable, aqueous or organic solvents,or mixtures thereof, and powders. The liquid or solid compositions maycontain suitable pharmaceutically acceptable excipients as describedsupra. The compositions are administered by the oral or nasalrespiratory route for local or systemic effect. Compositions inpharmaceutically acceptable solvents may be nebulized by use of inertgases. Nebulized solutions may be inhaled directly from the nebulizingdevice or the nebulizing device may be attached to a face mask tent, orintermittent positive pressure breathing machine. Solution, suspension,or powder compositions may be administered, for example orally ornasally, from devices that deliver the formulation in an appropriatemanner.

[0177] The following examples are included to demonstrate preferredembodiments of the invention. It should be appreciated by those of skillin the art that the techniques disclosed in the examples which followrepresent techniques discovered by the inventor to function well in thepractice of the invention, and thus can be considered to constitutepreferred modes for its practice. However, those of skill in the artshould, in light of the present disclosure, appreciate that many changescan be made in the specific embodiments which are disclosed and stillobtain a like or similar result without departing from the spirit andscope of the invention.

EXAMPLE 1 Preparation of a Compound of Formula (3)

[0178] A. Preparation of a Compound of Formula (3) where R¹ isCyclopentyl, R² is Hydrogen, and X is a Covalent Bond

[0179] To a solution of(2S,1R,4R,5R)-2-hydroxymethyl-5-(6-chloropurin-9-yl)-tetrahydrofuran-3,4-diolacetonide, the compound of formula (2) in which R² is hydrogen (4.98 g,15 mmol) in ethanol (80 ml) was added cyclopentylamine (0.6 ml, 30mmol), and triethylamine (6.27 ml, 45 mmol), and the mixture wasrefluxed for 16 hours. The solvent was then removed under reducedpressure, and the residue partitioned between ethyl acetate and 10%citric acid in water, followed by water. Ethyl acetate was removed fromthe organic layer, to yield{(1R,2R,4R,5R)-4-[6-(cyclopentylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}methan-1-ol,a compound of formula (3).

[0180] B. Preparation of Compounds of Formula (3), Varying X, R¹ and R²

[0181] Similarly, following the procedure of 1A above, but replacingcyclopentylamine with other amines of formula R¹XNH₂, the followingcompound of formula (3) was prepared:

[0182]{(1R,2R,4R,5R)-7,7-dimethyl-3,6,8-trioxa-4-[6-(oxolan-3-ylamino)purin-9-yl]bicyclo[3.3.0]oct-2-yl}methan-1-ol.

[0183] C. Preparation of Compounds of Formula (3), Varying X, R¹ and R²

[0184] Similarly, following the procedure of 1A above, but replacingcyclopentylamine with other amines of formula R¹XNH₂, the followingcompounds of formula (3) are prepared:

[0185]{(1R,2R,4R,5R)-4-[6-(cyclopentylmethylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}methan-1-ol;

[0186]{(1R,2R,4R,5R)-4-[2-trifluoromethyl-6-(cyclopentylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}methan-1-ol;

[0187]{(1R,2R,4R,5R)-4-[6-cyclobutylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}methan-1-ol;

[0188]{(1R,2R,4R,5R)-4-[6-cyclohexylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}methan-1-ol;

[0189]{(1R,2R,4R,5R)-4-[2-fluoro-6-cyclohexylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}methan-1-ol;

[0190]{(1R,2R,4R,5R)-4-[6-cyclohexylmethylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}methan-1-ol;

[0191]{(1R,2R,4R,5R)-4-[6-(3-fluorocyclopentylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}methan-1-ol;

[0192]{(1R,2R,4R,5R)-4-[6-(4-trifluoromethylcyclopentylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}methan-1-ol;

[0193]{(1R,2R,4R,5R)-4-[6-(3-methoxycyclopentylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}methan-1-ol;

[0194]{(1R,2R,4R,5R)-4-[6-(phenylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}methan-1-ol;

[0195]{(1R,2R,4R,5R)-4-[6-(benzylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}methan-1-ol;

[0196]{(1R,2R,4R,5R)-4-[6-(4-fluorophenylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}methan-1-ol;

[0197]{(1R,2R,4R,5R)-4-[6-(pyridin-3-ylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}methan-1-ol;

[0198]{(1R,2R,4R,5R)-4-[6-(thiazol-2-ylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}methan-1-ol;

[0199]{(1R,2R,4R,5R)-4-[6-(tetrahydropyran-3-ylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}methan-1-ol;

[0200]{(1R,2R,4R,5R)-4-[6-(tetrahydropyran-3-ylmethylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}methan-1-ol;and

[0201]{(1R,2R,4R,5R)-4-[6-(5-fluorotetrahydropyran-3-ylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}methan-1-ol.

[0202] D. Preparation of Compounds of Formula (3), Varying X, R¹ and R²

[0203] Similarly, following the procedure of 1A above, but replacingcyclopentylamine with other amines of formula R¹XNH₂, other compounds offormula (3) are prepared.

EXAMPLE 2 Preparation of a Compound of Formula (4)

[0204] A. Preparation of a Compound of Formula (4) where R¹ isCyclopentyl R² is Hydrogen and X is a Covalent Bond

[0205] A mixture of{(1R,2R,4R,5R)-4-[6-(cyclopentylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}methan-1-ol(0.94 g, 25 mmol), dimethylsulfoxide (7 ml), dicyclohexylcarbodimide(1.55 g) and pyridine (0.2 ml) was stirred at 0° C. for a few minutes,and then trifluoroacetic acid (0.1 ml) added. The mixture was allowed towarm to room temperature, and stirred for 18 hours. The mixture was thenpartitioned between ethyl acetate and water and washed with water.Solvent was removed from the organic layer under reduced pressure, andthe product,(2S,1R,4R,5R)-4-[6-(cyclopentylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]octane-2-carbaldehyde,a compound of formula (4).

[0206] B. Preparation of Compounds of Formula (4), Varying R¹

[0207] Similarly, following the procedure of 2A above, but replacing{(1R,2R,4R,5R)-4-[6-(cyclopentylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}methan-1-ol with{(1R,2R,4R,5R)-7,7-dimethyl-3,⁶,⁸-trioxa-4-[6-(oxolan-3-ylamino)purin-9-yl]bicyclo[3.3.0]oct-2-yl}methan-1-ol,the following compound of formula (4) was prepared:

[0208](2S,1R,4R,5R)-7,7-dimethyl-3,6,8-trioxa-4-[6-(oxolan-3-ylamino)purin-9-yl]bicyclo[3.3.0]octane-2-carboxaldehyde.

[0209] C. Preparation of Compounds of Formula (4), Varying X, R¹ and R²

[0210] Similarly, following the procedure of 2A above, but replacing{(1R,2R,4R,5R)-4-[6-(cyclopentylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}methan-1-olwith other compounds of formula (3), the following compounds of formula(4) are prepared:

[0211]{(1R,2R,4R,5R)-4-[6-(cyclopentylmethylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]octane-2-carboxaldehyde;

[0212]{(1R,2R,4R,5R)-4-[2-trifluoromethyl-6-(cyclopentylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]octane-2-carboxaldehyde;

[0213]{(1R,2R,4R,5R)-4-[6-cyclobutylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]octane-2-carboxaldehyde;

[0214]{(1R,2R,4R,5R)-4-[6-cyclohexylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]octane-2-carboxaldehyde;

[0215]{(1R,2R,4R,5R)-4-[2-fluoro-6-cyclohexylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]octane-2-carboxaldehyde;

[0216]{(1R,2R,4R,5R)-4-[6-cyclohexylmethylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]octane-2-carboxaldehyde;

[0217]{(1R,2R,4R,5R)-4-[6-(3-fluorocyclopentylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]octane-2-carboxaldehyde;

[0218]{(1R,2R,4R,5R)-4-[6-(4-trifluoromethylcyclopentylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]octane-2-carboxaldehyde;

[0219]{(1R,2R,4R,5R)-4-[6-(3-methoxycyclopentylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]octane-2-carboxaldehyde;

[0220]{(1R,2R,4R,5R)-4-[6-(phenylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]octane-2-carboxaldehyde;

[0221]{(1R,2R,4R,5R)-4-[6-(benzylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]octane-2-carboxaldehyde;

[0222]{(1R,2R,4R,5R)-4-[6-(4-fluorophenylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]octane-2-carboxaldehyde;

[0223]{(1R,2R,4R,5R)-4-[6-(pyridin-3-ylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]octane-2-carboxaldehyde;

[0224]{(1R,2R,4R,5R)-4-[6-(thiazol-2-ylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]octane-2-carboxaldehyde;

[0225]{(1R,2R,4R,5R)-4-[6-(tetrahydropyran-3-ylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]octane-2-carboxaldehyde;

[0226]{(1R,2R,4R,5R)-4-[6-(tetrahydropyran-3-ylmethylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]octane-2-carboxaldehyde;and

[0227]{(1R,2R,4R,5R)-4-[6-(5-fluorotetrahydropyran-3-ylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]octane-2-carboxaldehyde.

[0228] D. Preparation of Compounds of Formula (4), Varying X, R¹ and R²

[0229] Similarly, following the procedure of 2A above, but replacing{(1R,2R,4R,5R)-4-[6-(cyclopentylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}methan-1-olwith other compounds of formula (3), other compounds of formula (4) areprepared.

EXAMPLE 3 Preparation of a Compound of Formula (5)

[0230] A. Preparation of a Compound of Formula (5) where R¹ isCyclopentyl and R² is Hydrogen

[0231] To a suspension of potassium t-butoxide (0.84 g, 7.5 mmol) intetrahydrofuran (5 ml) at −78° C. was addedbromomethyltriphenylphosphonium (1.64 g, 3.75 mmol) in small portions,and the mixture stirred for 2 hours. To this mixture was added asolution of(2S,1R,4R,5R)-4-[6-(cyclopentylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]octane-2-carboxaldehyde(0.932 g, 2.5 mmol) in tetrahydrofuran (20 ml), and the mixture wasstirred for 2 hours at −78° C. The reaction mixture was then allowed towarm to room temperature and stirred for 6 days, then quenched withaqueous ammonium chloride, and partitioned between water and ethylacetate. The organic layer was separated, dried over magnesium sulfate,filtered, and the solvent removed from the filtrate under reducedpressure, to yield[9-((1R,2S,4R,5R)-4-ethynyl-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl)purin-9-yl]cyclopentylamine,a compound of formula (5).

[0232] B. Preparation of Compounds of Formula (5), Varying R¹

[0233] Similarly, following the procedure of 3A above, but replacing(2S,1R,4R,5R)-4-[6-(cyclopentylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]octane-2-carboxaldehydewith{(1R,2S,4R,5R)-7,7-dimethyl-3,6,8-trioxa-4-[6-(oxolan-3-ylamino)purin-9-yl]bicyclo[3.3.0]octane-2-carboxaldehyde,the following compound of formula (5) was prepared:

[0234] (1R,2R,4R,5R)-4-ethynyl-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl)-purin-9-ylamine.

[0235] C. Preparation of Compounds of Formula (4) Varying X, R¹ and R²

[0236] Similarly, following the procedure of 3A above, but replacing{(1R,2R,4R,5R)-4-[6-(cyclopentylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}methan-1-olwith other compounds of formula (3), the following compounds of formula(4) are prepared:

[0237]{(1R,2R,4R,5R)-4-ethynyl-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl-purin-9-yl]cyclopentylmethylamine;

[0238]{(1R,2R,4R,5R)-4-ethynyl-7,7-dimethyl-2-trifluoromethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl-purin-9-yl]cyclopentylamine;

[0239]{(1R,2R,4R,5R)-4-ethynyl-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl-purin-9-yl]cyclobutylamine;

[0240]{(1R,2R,4R,5R)-4-ethynyl-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl-purin-9-yl]cyclohexylamine;

[0241]{(1R,2R,4R,5R)-4-ethynyl-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl-purin-9-yl]2-flouro-6-cyclohexylamine;

[0242]{(1R,2R,4R,5R)-4-ethynyl-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl-purin-9-yl]cyclohexylmethylamine;

[0243]{(1R,2R,4R,5R)-4-ethynyl-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl-purin-9-yl](3-fluorocyclopentylamine;

[0244]{(1R,2R,4R,5R)-4-ethynyl-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl-purin-9-yl](4-trifluoromethylcyclopentylamine;

[0245]{(1R,2R,4R,5R)-4-ethynyl-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl-purin-9-yl](3-methoxycyclopentylamine;

[0246]{(1R,2R,4R,5R)-4-ethynyl-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl-purin-9-yl](phenylamine;

[0247]{(1R,2R,4R,5R)-4-ethynyl-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-y-purin-9-yl]benzylamine;

[0248]{(1R,2R,4R,5R)-4-ethynyl-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl-purin-9-yl](4-fluorophenylamine);

[0249]{(1R,2R,4R,5R)-4-ethynyl-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl-purin-9-yl](pyridin-3-ylamine;

[0250]{(1R,2R,4R,5R)-4-ethynyl-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-ylpurin-9-yl](thiazol-2-ylamine;

[0251]{(1R,2R,4R,5R)-4-ethynyl-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl-purin-9-yl](tetrahydropyran-3-ylamine);

[0252]{(1R,2R,4R,5R)-4-ethynyl-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl-purin-9-yl](tetrahydropyran-3-ylmethylamine;and

[0253]{(1R,2R,4R,5R)-4-ethynyl-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl-purin-9-yl](5-fluorotetrahydropyran-3-ylamine.

[0254] D. Preparation of Compounds of Formula (5), Varying X, R¹ and R²

[0255] Similarly, following the procedure of 3A above, but replacing{(1R,2R,4R,5R)-4-[6-(cyclopentylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}methan-1-olwith other compounds of formula (4), other compounds of formula (5) areprepared.

EXAMPLE 4 Preparation of a Compound of Formula I

[0256] A. Preparation of a Compound of Formula I where R¹ isCyclopentyl, R², R³, R⁴ and R⁵ are Hydrogen, X, X¹ and Y are CovalentBonds, and Z is —C≡C—

[0257] A solution of[9-((1R,2R,4R,5R)-4-ethynyl-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl)purin-6-yl]cyclopentylamine(0.28 g) was dissolved in 20 ml of a mixture of acetic acid:water(80:20) and stirred overnight at 75° C. Solvent was removed underreduced pressure, and the residue purified by preparative TLC, elutingwith methanol:methylene chloride (1:8), to yield(4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]-5-ethynyloxolane-3,4-diol,a compound of Formula I.

[0258] B. Preparation of a Compound of Formula I where R¹ isTetrahydrofuran-3-yl, R², R³, R⁴ and R⁵ are Hydrogen, X, X¹ and Y areCovalent Bonds, and Z is —C≡C—

[0259] Similarly, following the procedure of 4A above, but replacing[9-((1R,2R,4R,5R)-4-ethynyl-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl)purin-6-yl]cyclopentylaminewith (1R,2R,4R,5R)-4-ethynyl-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl)-purin-9-yl]oxolan-3-ylamine, the followingcompounds of Formula I are prepared:

[0260](4S,2R,3R,5R)-2-[6-(oxolan-3-ylamino)purin-9-yl]-5-ethynyloxolane-3,4-diol;

[0261](4S,2R,3R,5R)-2-[6-(cyclopentylmethylamino)purin-9-yl]-5-ethynyloxolane-3,4-diol;

[0262](4R,2R,3R,5R)-2-[2-trifluoromethyl-6-(cyclopentylamino)purin-9-yl]-5-ethynyloxolane-3,4-diol;

[0263](4S,2R,3R,5R)-2-[6-(cyclobutylamino)purin-9-yl]-5-ethynyloxolane-3,4-diol;

[0264](4S,2R,3R,5R)-2-[6-(cyclohexylamino)purin-9-yl]-5-ethynyloxolane-3,4-diol;

[0265](4S,2R,3R,5R)-2-[2-fluoro-6-(cyclohexylamino)purin-9-yl]-5-ethynyloxolane-3,4-diol;

[0266](4S,2R,3R,5R)-2-[6-(cyclohexylmethylamino)purin-9-yl]-5-ethynyloxolane-3,4-diol;

[0267](4S,2R,3R,5R)-2-[6-(3-fluorocyclopentylamino)purin-9-yl]-5-ethynyloxolane-3,4-diol;

[0268](4S,2R,3R,5R)-2-[6-(4-trifluoromethylcyclopentylamino)purin-9-yl]-5-ethynyloxolane-3,4-diol;

[0269](4S,2R,3R,5R)-2-[6-(3-methoxycyclopentylamino)purin-9-yl]-5-ethynyloxolane-3,4-diol;

[0270](4S,2R,3R,5R)-2-[6-(phenylamino)purin-9-yl]-5-ethynyloxolane-3,4-diol;

[0271](4S,2R,3R,5R)-2-[6-(benzylamino)purin-9-yl]-5-ethynyloxolane-3,4-diol;

[0272](4S,2R,3R,5R)-2-[6-(4-fluorophenylamino)purin-9-yl]-5-ethynyloxolane-3,4-diol;

[0273](4S,2R,3R,5R)-2-[6-(pyridin-3-ylamino)purin-9-yl]-5-ethynyloxolane-3,4-diol;

[0274](4S,2R,3R,5R)-2-[6-(thiazol-2-ylamino)purin-9-yl]-5-ethynyloxolane-3,4-diol;

[0275](4S,2R,3R,5R)-2-[6-(tetrahydropyran-3-ylamino)purin-9-yl]-5-ethynyloxolane-3,4-diol;

[0276](4S,2R,3R,5R)-2-[6-(tetrahydropyran-3-ylmethylamino)purin-9-yl]-5-ethynyloxolane-3,4-diol;and

[0277](4S,2R,3R,5R)-2-[6-(5-fluorotetrahydropyran-3-ylamino)purin-9-yl]-5-ethynyloxolane-3,4-diol;

[0278] C. Preparation of Compounds of Formula I, Varying X, R¹ and R²

[0279] Similarly, following the procedure of 4A above, but replacing[9-((1R,2R,4R,5R)-4-ethynyl-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl)purin-6-yl]cyclopentylaminewith other compounds of formula (5), other compounds of Formula I areprepared.

EXAMPLE 5 Preparation of a Compound of Formula (6)

[0280] A. Preparation of a Compound of Formula (6) where R¹ isCyclopentyl, R² is Hydrogen, R³ is 2-Trifluoromethylphenyl, Y is aCovalent Bond, and Z is —C≡C—

[0281] To a solution of[9-((1R,2R,4R,5R)-4-ethynyl-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl)purin-6-yl]cyclopentylamine(40 mg, 0.12 mmol), a compound of formula (5), in tetrahydrofuran (4 ml)under nitrogen was added catalytic amounts (3 mg) ofdichlorobis(triphenylphosphine)palladium(II) and copper(II)iodide,followed by 1-iodo-2-trifluoromethylbenzene (0.25 ml, 0.3 mmol).Triethylamine (0.4 ml) was then added, and the mixture stirred for 15minutes at room temperature. The solvent was removed under reducedpressure, and the residue was purified by preparative TLC, eluting withmethanol:methylene chloride (6.5:1), to yield[9-((1R,2R,4R,5R)-7,7-dimethyl-4-{2-[2-(trifluoromethyl)-phenyl]ethynyl}-3,6,8-trioxabicyclo[3.3.0]oct-2-yl)purin-6-yl]cyclopentylamine,a compound of formula (6).

[0282] B. Preparation of a Compound of Formula (6) where R¹ isCyclopentyl or Tetrahydrofuran-3-yl, R², R⁴ and R⁵ are Hydrogen, X, X¹and Y are Covalent Bonds, and Z is —C≡C—, varying R³

[0283] Similarly, following the procedure of 5A above, but replacing[9-((1R,2R,4R,5R)-4-ethynyl-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl)purin-6-yl]cyclopentylaminewith the appropriate compounds of formula (5), the following compoundsof formula (6) were prepared:

[0284] [9-((1R,2R,4R,5R)-7,7-dimethyl-4-{2-[2-(trifluoromethyl)phenyl]ethynyl}-3,6,8-trioxabicyclo[3.3.0]oct-2-yl)purin-6-yl]oxolan-3-ylamine;

[0285] [9-((1R,2R,4R,5R)-7,7-dimethyl-4-{2-[2-fluorophenyl]ethynyl}-3,6,8-trioxabicyclo[3.3.0]oct-2-yl)purin-6-yl]oxolan-3-ylamine;

[0286] [9-((1R,2R,4R,5R)-7,7-dimethyl-4-{2-[2-chlorophenyl]ethynyl}-3,6,8-trioxabicyclo[3.3.0]oct-2-yl)purin-6-yl]oxolan-3-ylamine;

[0287] [9-((1R,2R,4R,5R)-7,7-dimethyl-4-{2-[thien-2-yl]ethynyl}-3,6,8-trioxabicyclo[3.3.0]oct-2-yl)purin-6-yl]oxolan-3-ylamine;

[0288] [9-((1R,2R,4R,5R)-7,7-dimethyl-4-{2-[2-chlorophenyl]ethynyl}-3,6,8-trioxabicyclo[3.3.0]oct-2-yl)purin-6-yl]cyclopentylamine;and

[0289]{9-[(1R,2R,4R,5R)-7,7-dimethyl-4-(2-(2-thienyl)ethynyl)-3,6,8-trioxabicyclo[3.3.0]oct-2-yl]purin-6-yl}cyclopentylamine.

[0290] C. Preparation of a Compound of Formula (6), Varying R¹, R², R³,R⁴, R⁵, X, X¹ and Y, and Z is —C≡C—

[0291] Similarly, following the procedure of 5A above, but optionallyreplacing[9-((1R,2R,4R,5R)-4-ethynyl-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl)purin-6-yl]cyclopentylaminewith other compounds of formula (5), and optionally replacing1-iodo-2-trifluoromethylbenzene with other compounds of formula R³Y—LG,where LG is a leaving group, the following compounds of Formula I areprepared:

[0292][9-((1R,2R,4R,5R)-7,7-dimethyl-4-{2-[2-methylphenyl]ethynyl}-3,6,8-trioxabicyclo[3.3.0]oct-2-yl)purin-6-yl]cyclopentylamine;

[0293][9-((1R,2R,4R,5R)-7,7-dimethyl-4-{2-[2-fluorophenyl]ethynyl}-3,6,8-trioxabicyclo[3.3.0]oct-2-yl)purin-6-yl]cyclopentylamine;

[0294][9-((1R,2R,4R,5R)-7,7-dimethyl-4-{2-[phenylethynyl]-3,6,8-trioxabicyclo[3.3.0]oct-2-yl)purin-6-yl]cyclopentylamine;

[0295][9-((1R,2R,4R,5R)-7,7-dimethyl-4-{2-[5-chlorothien-2-yl]ethynyl}-3,6,8-trioxabicyclo[3.3.0]oct-2-yl)purin-6-yl]cyclopentylamine;

[0296][9-((1R,2R,4R,5R)-7,7-dimethyl-4-{2-[4-methylisoxazol-3-yl]ethynyl}-3,6,8-trioxabicyclo[3.3.0]oct-2-yl)purin-6-yl]cyclopentylamine;

[0297][9-((1R,2R,4R,5R)-7,7-dimethyl-4-{2-[3,5-dimethylisoxazol-4-yl]ethynyl}-3,6,8-trioxabicyclo[3.3.0]oct-2-yl)purin-6-yl]cyclopentylamine;

[0298][9-((1R,2R,4R,5R)-7,7-dimethyl-4-{2-[cyclopentyl]ethynyl}-3,6,8-trioxabicyclo[3.3.0]oct-2-yl)purin-6-yl]cyclopentylamine;

[0299][9-((1R,2R,4R,5R)-7,7-dimethyl-4-{2-[2-fluorocyclohexyl]ethynyl}-3,6,8-trioxabicyclo[3.3.0]oct-2-yl)purin-6-yl]cyclopentylamine;

[0300][9-((1R,2R,4R,5R)-7,7-dimethyl-4-{2-[piperidin-2-yl]ethynyl}-3,6,8-trioxabicyclo[3.3.0]oct-2-yl)purin-6-yl]cyclopentylamine;

[0301][9-((1R,2R,4R,5R)-7,7-dimethyl-4-{2-[4-methylpiperazin-1-yl]ethynyl}-3,6,8-trioxabicyclo[3.3.0]oct-2-trioxabicyclo[3.3.0]oct-2-yl)purin-6-yl]cyclopentylamine;

[0302][9-((1R,2R,4R,5R)-7,7-dimethyl-4-{2-[pyridin-2-yl]ethynyl}-3,6,8-trioxabicyclo[3.3.0]oct-2-yl)purin-6-yl]cyclopentylamine;

[0303][9-((1R,2R,4R,5R)-7,7-dimethyl-4-{2-[6-fluoropyridin-2-yl]ethynyl}-3,6,8-trioxabicyclo[3.3.0]oct-2-yl)purin-6-yl]cyclopentylamine;

[0304][9-((1R,2R,4R,5R)-7,7-dimethyl-4-{2-[thiazol-2-yl]ethynyl}-3,6,8-trioxabicyclo[3.3.0]oct-2-yl)purin-6-yl]cyclopentylamine;

[0305][9-((1R,2R,4R,5R)-7,7-dimethyl-4-{2-[pyrimidin-2-yl]ethynyl}-3,6,8-trioxabicyclo[3.3.0]oct-2-yl)purin-6-yl]cyclopentylamine;

[0306][9-((1R,2R,4R,5R)-7,7-dimethyl-4-{2-[2-fluorophenyl]ethynyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl-purin-6-yl]cyclopentylmethylamine;

[0307][9-((1R,2R,4R,5R)-2-trifluoromethyl-7,7-dimethyl-4-{2-[2-fluorophenyl]ethynyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl-purin-6-yl]cyclopentylmethylamine;

[0308][9-((1R,2R,4R,5R)-7,7-dimethyl-4-{2-[2-fluorophenyl]ethynyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl-purin-6-yl]cyclobutylamine;

[0309][9-((1R,2R,4R,5R)-7,7-dimethyl-4-{2-[2-fluorophenyl]ethynyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl-purin-6-yl]cyclohexylamine;

[0310][9-((1R,2R,4R,5R)-7,7-dimethyl-4-{2-[2-fluorophenyl]ethynyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl-purin-6-yl](2-fluorocyclohexyl)amine;

[0311][9-((1R,2R,4R,5R)-7,7-dimethyl-4-{2-[2-fluorophenyl]ethynyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl-purin-6-yl]cyclohexylmethylamine;

[0312][9-((1R,2R,4R,5R)-7,7-dimethyl-4-{2-[2-fluorophenyl]ethynyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl-purin-6-yl](3-fluorocyclopentylamine;

[0313][9-((1R,2R,4R,5R)-7,7-dimethyl-4-{2-[2-fluorophenyl]ethynyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl-purin-6-yl](4-trifluoromethylcyclopentylamine;

[0314][9-((1R,2R,4R,5R)-7,7-dimethyl-4-{2-[2-fluorophenyl]ethynyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl-purin-6-yl](3-methoxycyclopentylamine;

[0315][9-((1R,2R,4R,5R)-7,7-dimethyl-4-{2-[2-fluorophenyl]ethynyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl-purin-6-yl]phenylamine;

[0316][9-((1R,2R,4R,5R)-7,7-dimethyl-4-{2-[2-fluorophenyl]ethynyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl-purin-6-yl](4-fluorophenyl)amine;

[0317][9-((1R,2R,4R,5R)-7,7-dimethyl-4-{2-[2-fluorophenyl]ethynyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl-purin-6-yl]benzylamine;

[0318][9-((1R,2R,4R,5R)-7,7-dimethyl-4-{2-[2-fluorophenyl]ethynyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl-purin-6-yl]pyridin-3-ylamine;

[0319][9-((1R,2R,4R,5R)-7,7-dimethyl-4-{2-[2-fluorophenyl]ethynyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl-purin-6-yl]thiazol-2-ylamine;and

[0320][9-((1R,2R,4R,5R)-7,7-dimethyl-4-{2-[thien-2-yl]ethynyl}-3,6,8-trioxabicyclo[3.3.0]oct-2-yl)purin-6-yl](5-fluorooxolan-3-ylamine).

[0321] D. Preparation of Compounds of Formula I, Varying X R¹ and R²

[0322] Similarly, following the procedure of 5A above, but optionallyreplacing[9-((1R,2R,4R,5R)-4-ethynyl-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl)purin-6-yl cyclopentylamine with other compounds of formula(5), and optionally replacing 1-iodo-2-trifluoromethylbenzene with othercompounds of formula R³Y—LG, where LG is a leaving group, othercompounds of Formula I are prepared.

EXAMPLE 6 Preparation of a Compound of Formula I

[0323] A. Preparation of a Compound of Formula I where R¹ is CyclopentylR², R⁴ and R⁵ are Hydrogen R³ is 2-Trifluoromethylphenyl, X, X¹ and Yare Covalent Bonds, and Z is —C≡C—

[0324] a) To a solution of(4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]-5-ethynyloxolane-3,4-diol(40 mg, 0.12 mmol) in tetrahydrofuran (4 mL) under nitrogen was addedcatalytic amounts (3 mg) of(4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]-5-ethynyloxolane-3,4-diol(II) and copper (I) iodide, followed by 1-iodo-2-trifluoromethylbenzene(0.042 mL). Triethylamine (0.4 mL) was then added, and the mixture wasstirred for 15 minutes at room temperature. The solvent was removedunder reduced pressure, and the residue was purified by preparative TLC,eluting with methanol:methylene chloride (6.5:1), to yield(4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]-5-{2-[2-(trifluoromethyl)phenyl]ethynyl}-oxolane-3,4-diol,a compound of Formula I.

[0325] b) Alternatively, the acetonide protecting group was removed from[9-((1R,2R,4R,5R)-7,7-dimethyl-4-{2-[2-(trifluoromethyl)-phenyl]ethynyl}-3,6,8-trioxabicyclo[3.3.0]oct-2-yl)purin-6-yl]cyclopentylamine,a compound of formula (6), in the same manner as shown in Example 4 toprovide(4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]-5-{2-[2-(trifluoromethyl)phenyl]ethynyl}oxolane-3,4-diol,a compound of Formula I.

[0326] B. Preparation of a Compound of Formula I where R¹ is Cyclopentylor Tetrahydrofuran-3-yl, R², R⁴ and R⁵ are Hydrogen, X, X¹ and Y areCovalent Bonds, and Z is —C≡C—, Varying R³

[0327] Similarly, following the procedure of 6A(a) above, but optionallyreplacing(4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]-5-ethynyloxolane-3,4-diolwith other compounds of Formula I in which R³ is hydrogen, andoptionally replacing 1-iodo-2-trifluoromethylbenzene with othercompounds of formula R³Y—LG, where LG is a leaving group, or:

[0328] Following the procedure of 6A(b) above, but replacing[9-((lR,2R,4R,5R)-7,7-dimethyl-4-{2-[2-(trifluoromethyl)-phenyl]ethynyl}-3,6,8-trioxabicyclo[3.3.0]oct-2-yl)purin-6-yl]cyclopentylaminewith other compounds of formula (6);

[0329] the following compounds of Formula I were prepared:

[0330](4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]-5-{2-[2-fluorophenyl]-ethynyl}oxolane-3,4-diol;

[0331](4S,2R,3R,5R)-2-[6-(oxalan-3-ylamino)purin-9-yl]-5-{2-[2-(trifluoromethyl)phenyl]-ethynyl}oxolane-3,4-ethynyl}oxolane-3,4-diol;

[0332](4S,2R,3R,5R)-2-[6-(oxalan-3-ylamino)purin-9-yl]-5-{2-[2-fluorophenyl]ethynyl}oxolane-3,4-diol;

[0333](4S,2R,3R,5R)-2-[6-(oxalan-3-ylamino)purin-9-yl]-5-{2-[2-chlorophenyl]ethynyl}oxolane-3,4-diol;

[0334](4S,2R,3R,5R)-2-[6-(oxalan-3-ylamino)purin-9-yl]-5-{2-[thien-2-yl]ethynyl}oxolane-3,4-diol;and

[0335](4S,2R,3R,5R)-2-[6-cyclopentylamino)purin-9-yl]-5-{2-[thien-2-yl]ethynyl}oxolane-3,4-diol;

[0336] C. Preparation of a Compound of Formula I Varying R¹ R², R³, R⁴,R⁵, X, X¹ and Y, and Z is —C≡C—

[0337] Similarly, following the procedure of 6A(a) above, but optionallyreplacing(4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]-5-ethynyloxolane-3,4-diolwith other compounds of Formula I in which R³ is hydrogen, andoptionally replacing 1-iodo-2-trifluoromethylbenzene with othercompounds of formula R³Y—LG, where LG is a leaving group, or:

[0338] Following the procedure of 6A(b) above, but replacing[9-((1R,2R,4R,5R)-7,7-dimethyl-4-{2-[2-(trifluoromethyl)-phenyl]ethynyl}-3,6,8-trioxabicyclo[3.3.0]oct-2-yl)purin-6-yl]cyclopentylaminewith other compounds of formula (6);

[0339] the following compounds of Formula I are prepared:

[0340](4S,2R,3R,5R)-2-[6-cyclopentylamino)purin-9-yl]-5-{2-[phenyl]ethynyl}oxolane-3,4-diol;

[0341](4S,2R,3R,5R)-2-[6-cyclopentylamino)purin-9-yl]-5-{2-[2-chlorophenyl]ethynyl}oxolane-3,4-diol;

[0342](4S,2R,3R,5R)-2-[6-cyclopentylamino)purin-9-yl]-5-{2-[2-methylphenyl]ethynyl}oxolane-3,4-diol;

[0343](4S,2R,3R,5R)-2-[6-cyclopentylarnino)purin-9-yl]-5-{5-chlorothien-2-yl]ethynyl}oxolane-3,4-diol;

[0344](4S,2R,3R,5R)-2-[6-cyclopentylamino)purin-9-yl]-5-{2-[4-methylisoxazol-4-yl]ethynyl}oxolane-3,4-diol;

[0345](4S,2R,3R,5R)-2-[6-cyclopentylamino)purin-9-yl]-5-{2-[2,5-dimethylisoxazol-4-yl]ethynyl}oxolane-3,4-diol;

[0346](4S,2R,3R,5R)-2-[6-cyclopentylamino)purin-9-yl]-5-{2-[cyclopentyl]ethynyl}oxolane-3,4-diol;

[0347](4S,2R,3R,5R)-2-[6-cyclopentylamino)purin-9-yl]-5-{2-[2-fluorocyclohexyl]ethynyl}oxolane-3,4-diol;

[0348](4S,2R,3R,5R)-2-[6-cyclopentylamino)purin-9-yl]-5-{2-[piperidin-2-yl]ethynyl}oxolane-3,4-diol;

[0349](4S,2R,3R,5R)-2-[6-cyclopentylamino)purin-9-yl]-5-{2-[4-methylpiperazin-1-yl]ethynyl}oxolane-3,4-diol;

[0350](4S,2R,3R,5R)-2-[6-cyclopentylamino)purin-9-yl]-5-{2-[pyridin-2-yl]ethynyl}oxolane-3,4-diol;

[0351](4S,2R,3R,5R)-2-[6-cyclopentylamino)purin-9-yl]-5-{2-[6-fluoropyridin-2-yl]ethynyl}oxolane-3,4-diol;

[0352](4S,2R,3R,5R)-2-[6-cyclopentylamino)purin-9-yl]-5-{2-[thiazol-2-yl]ethynyl}oxolane-3,4-diol;

[0353](4S,2R,3R,5R)-2-[6-cyclopentylamino)purin-9-yl]-5-{2-[pyrimidin-2-yl]ethynyl}oxolane-3,4-diol;

[0354](4S,2R,3R,5R)-2-[6-cyclopentylmethylamino)purin-9-yl]-5-{2-[2-fluorophenyl]ethynyl}oxolane-3,4-diol;

[0355](4S,2R,3R,5R)-2-[6-(cyclopentylmethylamino)purin-9-yl]-5-{2-[2-fluorophenyl]-ethynyl}oxolane-3,4-diol;

[0356](4S,2R,3R,5R)-2-[6-(cyclobutylamino)purin-9-yl]-5-{2-[2-fluorophenyl]-ethynyl}oxolane-3,4-diol;

[0357](4S,2R,3R,5R)-2-[6-(cyclohexylamino)purin-9-yl]-5-{2-[2-fluorophenyl]-ethynyl}oxolane-3,4-diol;

[0358](4S,2R,3R,5R)-2-[6-(2-fluorocyclohexylamino)purin-9-yl]-5-{2-[2-fluorophenyl]-ethynyl}oxolane-3,4-diol;

[0359](4S,2R,3R,5R)-2-[6-(cyclohexylmethylamino)purin-9-yl]-5-{2-[2-fluorophenyl]-ethynyl}oxolane-3,4-diol;

[0360](4S,2R,3R,5R)-2-[6-(3-fluorocyclopentylamino)purin-9-yl]-5-{2-[2-fluorophenyl]-ethynyl}oxolane-3,4-diol;(4S,2R,3R,5R)-2-[6-(4-trifluoromethylcyclopentylamino)purin-9-yl]-5-{2-[2-fluorophenyl]-ethynyl}oxolane-3,4-diol;

[0361](4S,2R,3R,5R)-2-[6-(3-methoxycyclopentylamino)purin-9-yl]-5-{2-[2-fluorophenyl]-ethynyl}oxolane-3,4-diol;(4S,2R,3R,5R)-2-[6-(phenylamino)purin-9-yl]-5-{2-[2-fluorophenyl]-ethynyl}oxolane-3,4-diol;(4S,2R,3R,5R)-2-[6-(4-fluorophenylamino)purin-9-yl]-5-{2-[2-fluorophenyl]-ethynyl}oxolane-3,4-diol;

[0362](4S,2R,3R,5R)-2-[6-(benzylamino)purin-9-yl]-5-{2-[2-fluorophenyl]-ethynyl}oxolane-3,4-diol;

[0363](4S,2R,3R,5R)-2-[6-(pyridin-3-ylamino)purin-9-yl]-5-{2-[2-fluorophenyl]-ethynyl}oxolane-3,4-diol;

[0364](4S,2R,3R,5R)-2-[6-(thiazol-2-ylamino)purin-9-yl]-5-{2-[2-fluorophenyl]-ethynyl}oxolane-3,4-diol;

[0365](4S,2R,3R,5R)-2-[6-(oxolan-3-ylmethylamino)purin-9-yl]-5-{2-[2-fluorophenyl]-ethynyl}oxolane-3,4-diol;

[0366](4S,2R,3R,5R)-2-[6-(5-fluorooxolan-3-ylamino)purin-9-yl]-5-{2-[2-fluorophenyl]-ethynyl}oxolane-3,4-diol.

[0367] D. Preparation of a Compound of Formula I Varying R¹ R², R³, R⁴,R⁵, X, X¹ and Y, and Z is —C═C—

[0368] Similarly, following the procedure of 6A above, but replacing[9-((1R,2R,4R,5R)-7,7-dimethyl-4-{2-[2-(trifluoromethyl)-phenyl]ethynyl}-3,6,8-trioxabicyclo[3.3.0]oct-2-yl)purin-6-yl]cyclopentylaminewith other compounds of formula (6), other compounds of Formula I areprepared.

EXAMPLE 7 Preparation of a Compound of Formula (7)

[0369] Preparation of a Compound of Formula (7) where R¹ isTetrahydrofuran-3-yl, R² is Hydrogen, R³ is 4-Fluorophenyl, X and Y areCovalent Bonds, and Z is —CH═CH—

[0370] To a solution of(2S,1R,4R,5R)-7,7-dimethyl-3,6,8-trioxa-4-[6-(oxolan-3-ylamino)purin-9-yl]bicyclo[3.3.0]octane-2-carbaldehyde,a compound of formula (4) (200 mg), in methylene chloride (5 ml) wasadded (4-fluorophenyl)triphenylphosphonium bromide (459 mg, 1 mmol),followed by dropwise addition of an aqueous solution of 50% sodiumhydroxide. After addition was complete, the mixture was stirred for 2hours, then washed with water. The organic layer was separated, dried,and solvent removed under reduced pressure. The residue was purified bypreparative thin layer chromatography, eluting with ethyl acetate, togive pure(9-{4-[2-(4-fluorophenyl)vinyl](1R,2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}purin-6-yl)oxolan-3-ylamine,a compound of formula (7).

[0371] B. Preparation of a Compound of Formula (7) where R¹ isCyclopentyl or Tetrahydrofuran-3-yl, R², R⁴ and R⁵ are Hydrogen, X, X¹and Y are Covalent Bonds, and Z is —CH═CH—, Varying R³

[0372] Similarly, following the procedure of 7A above, but optionallyreplacing(2S,1R,4R,5R)-7,7-dimethyl-3,6,8-trioxa-4-[6-(oxolan-3-ylamino)purin-9-yl]bicyclo[3.3.0]octane-2-carbaldehydewith other compounds of formula (4), and optionally replacing(4-fluorophenyl)triphenylphosphonium bromide with other compounds offormula R³YCH₂P(PH)₃Br, the following compounds of formula (7) wereprepared:

[0373](9-{4-[2-(5-chlorothien-2-yl)vinyl](1R,2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}purin-6-yl)cyclopentylamine;

[0374](9-{4-[2-(3,5-dimethylisoxazol-4-yl]vinyl(1R,2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}purin-6-yl)cyclopentylamine;

[0375](9-{4-[2-(4-methylisoxazol-3-yl]vinyl(1R,2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}purin-6-yl)cyclopentylamine;

[0376](9-{4-[2-(2-methylphenyl]vinyl(1R,2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}purin-6-yl)cyclopentylamine;and

[0377](9-{4-[2-(phenyl]vinyl(1R,2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}purin-6-yl)cyclopentylamine.

[0378] C. Preparation of a Compound of Formula (7) Varying R¹, R², R³,R⁴, R⁵, X, X¹, Y,, and Z is—CH═CH—

[0379] Similarly, following the procedure of 7A above, but optionallyreplacing(2S,1R,4R,5R)-7,7-dimethyl-3,6,8-trioxa-4-[6-(oxolan-3-ylamino)purin-9-yl]bicyclo[3.3.0]octane-2-carbaldehydewith other compounds of formula (4), and optionally replacing(4-fluorophenyl)triphenylphosphonium bromide with other compounds offormula R³YCH₂P(PH)₃Br, the following compounds of Formula I areprepared:

[0380](9-{4-[2-(2-methylphenyl]vinyl(1R,2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}purin-6-yl)cyclopentylamine;

[0381](9-{4-[2-(2-fluorophenyl]vinyl(1R,2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}purin-6-yl)cyclopentylamine;

[0382](9-{4-[2-(phenyl]vinyl(1R,2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}purin-6-yl)cyclopentylamine;

[0383](9-{4-[2-(cyclopentyl]vinyl(1R,2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}purin-6-yl)cyclopentylamine;

[0384](9-{4-[2-(2-fluorocyclohexyl]vinyl(1R,2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}purin-6-yl)cyclopentylamine;

[0385](9-{4-[2-(piperidin-2-yl]vinyl(1R,2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}purin-6-yl)cyclopentylamine;

[0386](9-{4-[2-(4-methylpiperazin-1-yl]vinyl(1R,2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}purin-6-yl)cyclopentylamine;

[0387](9-{4-[2-(pyridin-2-yl]vinyl(1R,2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}purin-6-yl)cyclopentylamine;

[0388](9-{4-[2-(6-fluoropyridin-2-yl]vinyl(1R,2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}purin-6-yl)cyclopentylamine;

[0389](9-{4-[2-(thiazol-2-yl]vinyl(1R,2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}purin-6-yl)cyclopentylamine;

[0390](9-{4-[2-(pyrimidin-2-yl]vinyl(1R,2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}purin-6-yl)cyclopentylamine;

[0391](9-{4-[2-(2-fluorophenyl)vinyl](1R,2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}purin-6-yl)cyclopentylmethylamine;

[0392](9-{4-[2-(2-fluorophenyl)vinyl](1R,2R,4R,5R)-7,7-dimethyl-2-trifluoromethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}purin-6-yl)cyclopentylmethylamine;

[0393](9-{4-[2-(2-fluorophenyl)vinyl](1R,2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}purin-6-yl)cyclobutylmethylamine;

[0394](9-{4-[2-(2-fluorophenyl)vinyl](1R,2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}purin-6-yl)cyclohexylamine;

[0395](9-{4-[2-(2-fluorophenyl)vinyl](1R,2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}purin-6-yl)(2-fluorocyclohexylamine);

[0396](9-{4-[2-(2-fluorophenyl)vinyl](1R,2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}purin-6-yl)cyclohexylmethylamine;

[0397](9-{4-[2-(2-fluorophenyl)vinyl](1R,2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}purin-6-yl)(3-fluorocyclopentylamine);

[0398](9-{4-[2-(2-fluorophenyl)vinyl](1R,2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}purin-6-yl)(4-trifluoromethylcyclopentylamine);

[0399](9-{4-[2-(2-fluorophenyl)vinyl](1R,2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}purin-6-yl)(3-methoxycyclopentylamine);

[0400](9-{4-[2-(2-fluorophenyl)vinyl](1R,2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}purin-6-yl)phenylamine;

[0401](9-{4-[2-(2-fluorophenyl)vinyl](1R,2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}purin-6-yl)(4-fluorophenylamine);

[0402](9-{4-[2-(2-fluorophenyl)vinyl](1R,2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicycyclo[3.3.0]oct-2-yl}purin-6-yl)benzylamine;

[0403](9-{4-[2-(2-fluorophenyl)vinyl](1R,2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicycyclo[3.3.0]oct-2-yl}purin-6-yl)pyridin-3-ylamine);

[0404](9-{4-[2-(2-fluorophenyl)vinyl](1R,2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}purin-6-yl)thiazol-2-ylamine;and

[0405](9-{4-[2-(2-fluorophenyl)vinyl](1R,2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}purin-6-yl)(5-fluorooxolan-3-ylamine).

[0406] D. Preparation of a Compound of Formula (7) Varying R¹, R², R³,R⁴, R⁵, X, X¹ Y,, and Z is —CH═CH—

[0407] Similarly, following the procedure of 7A above, but optionallyreplacing(2S,1R,4R,5R)-7,7-dimethyl-3,6,8-trioxa-4-[6-(oxolan-3-ylamino)purin-9-yl]bicyclo[3.3.0]octane-2-carbaldehyde with other compounds of formula (4), andoptionally replacing (4-fluorophenyl)triphenylphosphonium bromide withother compounds of formula R³YCH₂P(PH)₃Br, other compounds of Formula Iare prepared.

EXAMPLE 8 Preparation of a Compound of Formula I

[0408] A. Preparation of a Compound of Formula I where R¹ isTetrahydrofuran-3-yl, R² is Hydrogen, R³ is 4-Fluorophenyl, X and Y areCovalent Bonds, and Z is —CH═CH—

[0409] The acetonide protecting group was then removed from(9-{4-[(1E)-2-(4-fluorophenyl)vinyl](1R,2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}purin-6-yl)oxolan-3-ylamine,a compound of formula (7), in the same manner as shown in Example 4 toprovide5-[2-(4-fluorophenyl)vinyl]-2-[6-(oxolan-3-ylamino)purin-9-yl]oxolane-3,4-diol,a compound of Formula I.

[0410] B. Preparation of a Compound of Formula I where R¹ is Cyclopentylor Tetrahydrofuran-3-yl, R², R⁴ and R⁵ are Hydrogen. X, X¹ and Y areCovalent Bonds, and Z is —CH═CH—, Varying R³

[0411] Similarly, following the procedure of 8A above, but replacing(9-{4-[(1E)-2-(4-fluorophenyl)vinyl](1R,2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}purin-6-yl)oxolan-3-ylaminewith other compounds of formula (7), the following compounds of FormulaI were prepared:

[0412]5-[(1E)-2-(methoxycarbonylvinyl](4S,2R,3R,5R)-2-[6-(oxolan-3-ylamino)purin-9-yl]oxolane-3,4-diol;

[0413] 5-[(1E)-2-(2-methylphenyl)vinyl](4S,2R,3R,5R)-2-[6-(oxolan-3-ylamino)purin-9-yl]oxolane-3,4-diol;

[0414]5-[2-(5-chlorothien-2-yl)vinyl](4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]oxolane-3,4-diol;

[0415]5-[2-(4-dimethylisoxazol-4-yl)vinyl](4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]oxolane-3,4-diol;

[0416]5-[2-(4-methylisoxazol-3-yl)vinyl](4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]oxolane-3,4-diol;

[0417]5-[2-(2-methylphenyl)vinyl](4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]oxolane-3,4-diol;and

[0418]5-[2-(phenyl)vinyl](4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]oxolane-3,4-diol;

[0419] C. Preparation of a Compound of Formula I Varying R¹, R², R³, R⁴,R⁵, X X¹, Y,, and Z is—CH═CH—

[0420] Similarly, following the procedure of 8A above, but replacing(9-{4-[(1E)-2-(4-fluorophenyl)vinyl](1R,2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}purin-6-yl)oxolan-3-ylaminewith other compounds of formula (7), the following compounds of FormulaI are prepared:

[0421]5-[2-(2-methylphenyl)vinyl](4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]oxolane-3,4-diol,

[0422]5-[2-(2-fluorophenyl)vinyl](4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]oxolane-3,4-diol,

[0423]5-[2-(phenyl)vinyl](4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]oxolane-3,4-diol,

[0424]5-[2-(cyclopentyl)vinyl](4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]oxolane-3,4-diol,

[0425]5-[2-(2-fluorocyclohexyl)vinyl](4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]oxolane-3,4-diol,

[0426]5-[2-(2-piperidin-2-yl)vinyl](4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]oxolane-3,4-diol,

[0427]5-[2-(4-methylpiperazin-1-yl)vinyl](4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]oxolane-3,4-diol,

[0428]5-[2-(2-pyridin-2-yl)vinyl](4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]oxolane-3,4-diol,

[0429]5-[2-(6-fluoropyridin-2-yl)vinyl](4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]oxolane-3,4-diol,

[0430]5-[2-(2-thiazol-2-yl)vinyl](4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]oxolane-3,4-diol,

[0431]5-[2-(pyrimidin-2-yl)vinyl](4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]oxolane-3,4-diol,

[0432]5-[2-(2-fluorophenyl)vinyl](4S,2R,3R,5R)-2-[6-(cyclopentylmethylamino)purin-9-yl]oxolane-3,4-diol,

[0433]5-[2-(2-fluorophenyl)vinyl](4S,2R,3R,5R)-2-[6-(cyclobutylmethylamino)purin-9-yl]oxolane-3,4-diol,

[0434]5-[2-(2-fluorophenyl)vinyl](4S,2R,3R,5R)-2-[6-(cyclohexylamino)purin-9-yl]oxolane-3,4-diol,

[0435]5-[2-(2-fluorophenyl)vinyl](4S,2R,3R,5R)-2-[6-(2-fluorocyclohexylamino)purin-9-yl]oxolane-3,4-diol,

[0436]5-[2-(2-fluorophenyl)vinyl](4S,2R,3R,5R)-2-[6-(2-fluorocyclohexylmethylamino)purin-9-yl]oxolane-3,4-diol,

[0437] 5-[2-(2-fluorophenyl)vinyl](4S,2R,3R,5R)-2-[6-(3-fluorocyclopentylamino)purin-9-yl]oxolane-3,4-diol,

[0438]5-[2-(2-fluorophenyl)vinyl](4S,2R,3R,5R)-2-[⁶-(4-trifluoromethylcyclopentylamino)purin-9-yl]oxolane-3,4-diol,

[0439]5-[2-(2-fluorophenyl)vinyl](4S,2R,3R,5R)-2-[6-(3-methoxycyclopentylamino)purin-9-yl]oxolane-3,4-diol,

[0440]5-[2-(2-fluorophenyl)vinyl](4S,2R,3R,5R)-2-[6-(phenylamino)purin-9-yl]oxolane-3,4-diol,

[0441]5-[2-(2-fluorophenyl)vinyl](4S,2R,3R,5R)-2-[6-(benzylamino)purin-9-yl]oxolane-3,4-diol,

[0442]5-[2-(2-fluorophenyl)vinyl](4S,2R,3R,5R)-2-[6-(pyridin-3-ylamino)purin-9-yl]oxolane-3,4-diol,

[0443]5-[2-(2-fluorophenyl)vinyl](4S,2R,3R,5R)-2-[6-(thiazol-2-ylamino)purin-9-yl]oxolane-3,4-diol,and

[0444]5-[2-(2-fluorophenyl)vinyl](4S,2R,3R,5R)-2-[6-(5-fluorooxolan-3-ylamino)purin-9-yl]oxolane-3,4-diol.

[0445] D. Preparation of a Compound of Formula I Varying R¹, R², R³, R⁴,R⁵, X, X¹, Y,, and Z is—CH═CH—

[0446] Similarly, following the procedure of 8A above, but replacing(9-{4-[(1E)-2-(4-fluorophenyl)vinyl](1R,2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}purin-6-yl)oxolan-3-ylaminewith other compounds of formula (7), other compounds of Formula I areprepared.

EXAMPLE 9 Preparation of a Compound of Formula I

[0447] Preparation of a Compound of Formula I where R¹ isTetrahydrofuran-3-yl, R² is Hydrogen, R³ is 4-Fluorophenyl, X and Y areCovalent Bonds, and Z is —CH CH₂—

[0448] To a solution of5-[2-(4-fluorophenyl)vinyl](4S,2R,3R,5R)-2-[6-(oxolan-3-ylamino)purin-9-yl]oxolane-3,4-diol(40 mg) in ethanol (5 ml) and cyclohexene (2 ml) was added palladiumhydroxide (50 mg), and the mixture was stirred for 24 hours. Thecatalyst was filtered off, and solvent removed under reduced pressure.The residue was purified by preparative thin layer chromatography, togive pure(4S,2R,3R,5R)-5-[2-(4-fluorophenyl)ethyl]-2-[6-(oxolan-3-ylamino)purin-9-yl]oxolane-3,4-diol,a compound of Formula I.

[0449] B. Preparation of a Compound of Formula I where R¹ is Cyclopentylor Tetrahydrofuran-3-yl, R², R⁴ and R⁵ are Hydrogen, X, X¹ and Y areCovalent Bonds, and Z is —CH₂CH₂—, Varying R³

[0450] Similarly, following the procedure of 9A above, but replacing5-[2-(4-fluorophenyl)vinyl](4S,2R,3R,5R)-2-[6-(oxolan-3-ylamino)purin-9-yl]oxolane-3,4-diolwith other compounds of Formula I in which Z is —CH═CH—, the followingcompounds of Formula I were prepared:

[0451](4S,2R,3R,5R)-5-[2-(methoxycarbonyl)ethyl]-2-[6-(oxolan-3-ylamino)purin-9-yl]oxolane-3,4-diol;

[0452](4S,2R,3R,5R)-5-[2-(2-methylphenyl)ethyl]2-[6-(oxolan-3-ylamino)purin-9-yl]oxolane-3,4-diol;

[0453](4S,2R,3R,5R)-5-[2-phenylethyl]2-[6-(cyclopentylamino)purin-9-yl]oxolane-3,4-diol;

[0454](4S,2R,3R,5R)-5-[2-(3,5-dimethylisoxazol-4-yl)ethyl]2-[6-(cyclopentylylamino)purin-9-yl]oxolane-3,4-diol;

[0455](4S,2R,3R,5R)-5-[2-(5-chlorothien-2-yl)ethyl]2-[6-(cyclopentylamino)purin-9-yl]oxolane-3,4-diol.

[0456] C. Preparation of a Compound of Formula I Varying R¹, R², R³, R⁴and R⁵ X, X¹, Y, and Z 5 is —CH₂CH₂—

[0457] Similarly, following the procedure of 9A above, but replacing5-[2-(4-fluorophenyl)vinyl](4S,2R,3R,5R)-2-[6-(oxolan-3-ylamino)purin-9-yl]oxolane-3,4-diolwith other compounds of Formula I in which Z is —CH═CH—, the followingcompounds of Formula I are prepared:

[0458](4S,2R,3R,5R)-5-[2-(4-methylisoxazol-3-yl)ethyl]-2-[6-(cyclopentylamino)purin-9-yl]oxolane-3,4-diol;

[0459](4S,2R,3R,5R)-5-[2-(2-methylphenyl)ethyl]-2-[6-(cyclopentylylamino)purin-9-yl]oxolane-3,4-diol;

[0460](4S,2R,3R,5R)-5-[2-(2-methylphenyl)ethyl]-2-[6-(oxolan-3-ylamino)purin-9-yl]oxolane-3,4-diol;

[0461](4S,2R,3R,5R)-5[2-(2-fluorophenyl)ethyl]-2-[6-(cyclopentylamino)purin-9-yl]oxolane-3,4-diol,

[0462](4S,2R,3R,5R)-5[2-(phenyl)ethyl]-2-[6-(cyclopentylamino)purin-9-yl]oxolane-3,4-diol,

[0463](4S,2R,3R,5R)-5[2-(cyclopentyl)ethyl]-2-[6-(cyclopentylamino)purin-9-yl]oxolane-3,4-diol,

[0464](4S,2R,3R,5R)-5[2-(2-fluorocyclohexyl)ethyl]-2-[6-(cyclopentylamino)purin-9-yl]oxolane-3,4-diol,

[0465](4S,2R,3R,5R)-5[2-(2-piperidin-2-yl)ethyl]-2-[6-(cyclopentylamino)purin-9-yl]oxolane-3,4-diol,

[0466](4S,2R,3R,5R)-5[2-(4-methylpiperazin-1-yl)ethyl]-2-[6-(cyclopentylamino)purin-9-yl]oxolane-3,4-diol,

[0467](4S,2R,3R,5R)-5[2-(2-pyridin-2-yl)ethyl]-2-[6-(cyclopentylamino)purin-9-yl]oxolane-3,4-diol,

[0468](4S,2R,3R,5R)-5[2-(6-fluoropyridin-2-yl)ethyl]-2-[6-(cyclopentylamino)purin-9-yl]oxolane-3,4-diol,

[0469](4S,2R,3R,5R)-5[2-(2-thiazol-2-yl)ethyl]-2-[6-(cyclopentylamino)purin-9-yl]oxolane-3,4-diol,

[0470](4S,2R,3R,5R)-5[2-(pyrimidin-2-yl)ethyl]-2-[6-(cyclopentylamino)purin-9-yl]oxolane-3,4-diol,(4S,2R,3R,5R)-5[2-(2-fluorophenyl)ethyl]-2-[6-(cyclopentylmethylamino)purin-9-yl]oxolane-3,4-3,4-diol,

[0471](4S,2R,3R,5R)-5[2-(2-fluorophenyl)ethyl]-2-[6-(cyclobutylmethylamino)purin-9-yl]oxolane-3,4-3,4-diol,

[0472](4S,2R,3R,5R)-5[2-(2-fluorophenyl)ethyl]-2-[6-(cyclohexylamino)purin-9-yl]oxolane-3,4-3,4-diol,

[0473](4S,2R,3R,5R)-5[2-(2-fluorophenyl)ethyl]-2-[6-(2-fluorocyclohexylamino)purin-9-yl]oxolane-3,4-3,4-diol,

[0474](4S,2R,3R,5R)-5[2-(2-fluorophenyl)ethyl]-2-[6-(2-fluorocyclohexylmethylamino)purin-9-yl]oxolane-3,4-3,4-diol,

[0475](4S,2R,3R,5R)-5[2-(2-fluorophenyl)ethyl]-2-[6-(3-fluorocyclopentylamino)purin-9-yl]oxolane-3,4-3,4-diol,

[0476](4S,2R,3R,5R)-5[2-(2-fluorophenyl)ethyl]-2-[6-(4-trifluoromethylcyclopentylamino)purin-9-yl]oxolane-3,4-3,4-diol,

[0477](4S,2R,3R,5R)-5[2-(2-fluorophenyl)ethyl]-2-[6-(3-methoxycyclopentylamino)purin-9-yl]oxolane-3,4-3,4-diol,

[0478](4S,2R,3R,5R)-5[2-(2-fluorophenyl)ethyl]-2-[6-(phenylamino)purin-9-yl]oxolane-3,4-3,4-diol,

[0479](4S,2R,3R,5R)-5[2-(2-fluorophenyl)ethyl]-2-[6-(benzylamino)purin-9-yl]oxolane-3,4-3,4-diol,

[0480](4S,2R,3R,5R)-5[2-(2-fluorophenyl)ethyl]-2-[6-(pyridin-3-ylamino)purin-9-yl]oxolane-3,4-3,4-diol,

[0481](4S,2R,3R,5R)-5[2-(2-fluorophenyl)ethyl]-2-[6-(thiazol-2-ylamino)purin-9-yl]oxolane-3,4-3,4-diol,and

[0482](4S,2R,3R,5R)-5[2-(2-fluorophenyl)ethyl]-2-[6-(5-fluorooxolan-3-ylamino)purin-9-yl]oxolane-3,4-3,4-diol.

[0483] D. Preparation of a Compound of Formula I Varying R¹ R². R³, R⁴and R⁵, X, X¹, Y, and Z is —CH₂CH₂—

[0484] Similarly, following the procedure of 9A above, but replacing5-[2-(4-fluorophenyl)vinyl](4S,2R,3R,5R)-2-[6-(oxolan-3-ylamino)purin-9-yl]oxolane-3,4-diolwith other compounds of Formula I in which Z is —CH═CH—, other compoundsof Formula I are prepared.

EXAMPLE 10

[0485] Preparation of a Compound of Formula (8) where R¹ is Cyclopentyland R² is Hydrogen

[0486] To a stirred solution of benzyloxymethyltriphenyl phosphoniumchloride (7.71 g, 18.40 mmol) in tetrahydrofuran (40 mL) was addedN-sodiumhexamethyldisilazane (1M in THF, 17.50 mL) dropwise, and themixture was stirred at −78° C. for 1 hour. Then{(2S,1R,4R)-4-[6-(cyclopentylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}formaldehyde,a compound of formula (4) (3.73 g, 10 mmol), was dissolved intetrahydrofuran (10 mL) and added slowly. The mixture was slowly broughtto room temperature, and stirred overnight, quenched with H₂O (60 mL)and extracted with ethyl acetate (3×50 mL). The combined organic layerswas washed with water (2×50 mL), dried over Na₂SO₄, and evaporated underreduced pressure. Column chromatography gave(9-{4-[2-(phenylmethoxy)vinyl](2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}purin-6-yl)cyclopentylamine,a compound of formula (8).

EXAMPLE 11

[0487] Preparation of a Compound of Formula (9) where R¹ is Cyclopentyland R² is Hydrogen.

[0488] A mixture of(9-{4-[(1E)-2-(phenylmethoxy)vinyl](2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}purin-6-yl)cyclopentylamine,a compound of formula (8)(1.90 g, 3.98 mmol) and catalytic amount ofPd/C in methanol (30 mL) was stirred under hydrogen (67 psi) overnight.The Pd/C was filtered through celite and washed with methanol. Thefiltrate was concentrated and the residue,(9-{4-[(1E)-2-(phenylmethoxy)vinyl](2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}purin-6-yl)cyclopentylamine,a compound of formula (9), was used without further purification.

EXAMPLE 12

[0489] Preparation of a Compound of Formula (10) where R¹ is cyclopentyland R² is Hydrogen.

[0490] A mixture of(9-{4-[(1E)-2-(phenylmethoxy)vinyl](2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}purin-6-yl)cyclopentylamine,a compound of formula (9), and Pd(OH)₂ in cyclohexene (45 mL) andethanol (30 mL) was stirred at 80° C. for 5 days. The mixture wasfiltered through celite and washed with ethanol. The filtrate wasconcentrated under reduced pressure, and the residue purified by columnchromatography to give2-{(1R,2R,4R)-4-[6-(cyclopentylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}ethan-1-ol,a compound of the Formula (10).

EXAMPLE 13

[0491] Preparation of a Compound of Formula (11) where R¹ is cyclopentyland R² is Hydrogen.

[0492] To an ice-cooled solution of2-{(1R,2R,4R)-4-[6-(cyclopentylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}ethan-1-ol,a compound of the Formula (10) (0.90 g 2.31 mmol),dicyclohexylcarbodiimide (1.43 g, 6.93 mmol) and pyridine (0.19 mL, 2.31mmol) in dimethylsulfoxide (16 mL) was added trifluoroacetic acid (0.09mL, 1.15 mmol) slowly. The resulting mixture was stirred under N₂ atroom temperature overnight. N,N′-dicyclohexylurea was then filtered off,and washed with ethyl acetate (60 mL). The filtrate was washed withwater (3×40 mL), dried over Na₂SO₄, and concentrated under reducedpressure. The residue,2-{3(1R,2R,4R)-4-[6-(cyclopentylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}ethan-1-one,a compound of Formula (11) was used without further purification.

EXAMPLE 14

[0493] Preparation of a Compound of Formula (12) where R¹ is Cyclopentyland R² is Hydrogen.

[0494] To a stirred solution of potassium-tert-butoxide (0.78 g, 6.93mmol) in tetrahydrofuran (45 mL) was added(bromomethyl)triphenylphosphonium bromide (1.51 g, 3.27 mmol) in smallportions at −78° C. The resulting mixture was stirred at -78° C. for 2hours.2-{(1R,2R,4R)-4-[6-(cyclopentylamino)purin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl}ethan-1-one,a compound of Formula (11) (0.89 g, 2.31 mmol) dissolved in THF (15 mL)was added slowly. and the mixture stirred under an atmosphere of N₂ at−78° C. for 3 hours, brought to room temperature slowly and stirred for4 days. The reaction mixture was quenched with saturated NH₄Cl aqueoussolution (15 mL) and diluted with H₂O (60 mL), and then extracted withEtOAc (3×50 mL). The combined organic layers were washed with H₂O (2×50mL), dried over Na₂SO₄, and evaporated under reduced pressure, toprovide{9-[4-((2E)-3-bromoprop-2-enyl)(2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl]purin-6-yl}cyclopentylamine,a compound of formula (12), which was isolated by column chromatography.

[0495] To a stirred solution of{9-[4-((2E)-3-bromoprop-2-enyl)(2R,4R,5R)-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl]purin-6-yl}cyclopentylamine,(0.40 g, 0.86 mmol) in tetrahydrofuran (25 mL) was addedpotassium-tert-butoxide (0.78 g, 6.93 mmol) in small portions at −78° C.The resulting mixture was stirred at −78° C. for 30 minutes, thenbrought to room temperature slowly and stirred overnight. The reactionmixture was quenched with saturated aqueous ammonium chloride solution(5 mL) and diluted with H₂O (30 mL), then extracted with EtOAc (3×30mL). The combined organic layers were washed with water (2×30 mL), driedover sodium sulfate, filtered, and the filtrate evaporated under reducedpressure, to provide[9-((2R,4R,5R)-7,7-dimethyl-3,6,8-trioxa-4-prop-2-ynylbicyclo[3.3.0]oct-2-yl)purin-6-yl]cyclopentylamine,a compound of formula (13), which was isolated by column chromatography.

EXAMPLE 15 Preparation of a Compound of Formula I

[0496] Preparation of a Compound of Formula I where R¹ is Cyclopentyl,R² and R³ are Hydrogen, X and Y are Covalent Bonds, X¹ is —CH₂—and Z is—C≡C—

[0497][9-((2R,4R,5R)-7,7-dimethyl-3,6,8-trioxa-4-prop-2-ynylbicyclo[3.3.0]oct-2-yl)purin-6-yl]cyclopentylamine,a compound of formula (13), was stirred in 80% acetic acid aqueoussolution (20 mL) at 80° C. in a sealed tube for 2 days. The solvent wasremoved under reduced pressure, and the residue purified by preparativethin layer chromatography, to give(4S,2R,5R)-2-[6-(cyclopentylamino)purin-9-yl]-5-prop-2-ynyloxolane-3,4-diol,a compound of Formula I.

EXAMPLE 16 Preparation of a Compound of Formula I

[0498] A. Preparation of a Compound of Formula I where R¹ isCyclopentyl, R² is Hydrogen, R³ is 2-Fluorophenyl, X and Y are CovalentBonds, X¹ is —CH₂—and Z is —C≡C—

[0499] To a stirred solution of(4S,2R,5R)-2-[6-(cyclopentylamino)purin-9-yl]-5-prop-2-ynyloxolane-3,4-diol(0.017 g, 0.05 mmol) and 1-fluoro-2-iodobenzene (0.02 mL, 0.13 mmol) inTHF (3.50 mL) under an atmosphere of N₂ was added catalytic amount ofdichlorobis(triphenylphosphine) palladium (II) and copper (I) iodide.Et₃N (0.20 mL) was then added. The resulting mixture was stirred underN₂ at 75° C. for 2 days. The solvent was removed under reduced pressure,and the residue was purified by preparative thin layer chromatography togive(4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]-5-[3-(2-fluorophenyl)prop-2-ynyl]oxolane-3,4-diol,a compound of Formula I.

[0500] B. Preparation of a Compound of Formula I where R¹ isCyclopentyl, R²R⁴ and R⁵ are Hydrogen, X and X¹ are Covalent Bonds, Y isCH₂, and Z is —C≡C—, Varying R³

[0501] Similarly, following the procedures of Examples 10-16 above, thefollowing compounds of Formula I in which X¹ is —CH₂—and Z is —C≡C—,were prepared:

[0502](4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]-5-{3-[2-fluorophenyl]prop-2-ynyl}oxolane-3,4-diol;and

[0503](4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]-5-{3-[2-(trifluoromethyl)phenyl]prop-2-ynyl}oxolane-3,4-diol.

[0504] C. Preparation of a Compound of Formula I Varying R¹, R², R³, R⁴and R⁵, X, X¹ and Y is CH₂, and Z is —C≡C—

[0505] Similarly, following the procedures of Examples 10-16 above, thefollowing compounds of Formula I in which X¹ is —CH₂—and Z is —C—C— areprepared:

[0506](4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]-5-{3-[4-methylisoxazol-3-yl]prop-2-ynyl}oxolane-3,4-diol;

[0507](4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]-5-{3-[2-methylphenyl]prop-2-ynyl}oxolane-3,4-diol;

[0508](4S,2R,3R,5R)-2-[6-(oxolan-3-ylamino)purin-9-yl]-5-{3-[2-fluorophenyl]prop-2-ynyl}oxolane-3,4-diol;

[0509](4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]-5-{3-[2-fluorophenyl]prop-2-ynyl}oxolane-3,4-diol;

[0510](4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]-5-{3-[phenyl]prop-2-ynyl}oxolane-3,4-diol;

[0511](4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]-5-{3-[cyclopentyl]prop-2-ynyl}oxolane-3,4-diol;

[0512](4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]-5-{3-[2-fluorocyclohexyl]prop-2-ynyl}oxolane-3,4-diol;

[0513](4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]-5-{3-[piperidin-2-yl]prop-2-ynyl}oxolane-3,4-diol;

[0514](4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]-5-{3-[4-methylpiperazin-1-yl]prop-2-ynyl}oxolane-3,4-diol;

[0515](4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]-5-{3-[pyridin-2-yl]prop-2-ynyl}oxolane-3,4-diol;

[0516](4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]-5-{3-[6-fluoropyridin-2-yl]prop-2-ynyl}oxolane-3,4-diol;

[0517](4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]-5-{3-[thiazol-2-yl]prop-2-ynyl}oxolane-3,4-diol;

[0518](4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]-5-{3-[pyrimidin-2-yl]prop-2-ynyl}oxolane-3,4-diol;

[0519](4S,2R,3R,5R)-2-[6-(cyclopentylmethylamino)purin-9-yl]-5-{3-[2-fluorophenyl]prop-2-ynyl}oxolane-3,4-diol;

[0520](4S,2R,3R,5R)-2-[6-(cyclobutylmethylamino)purin-9-yl]-5-{3-[2-fluorophenyl]prop-2-ynyl}oxolane-3,4-diol;

[0521](4S,2R,3R,5R)-2-[6-(cyclohexylamino)purin-9-yl]-5-{3-[2-fluorophenyl]prop-2-ynyl}oxolane-3,4-diol;

[0522](4S,2R,3R,5R)-2-[6-(2-fluorocyclohexylamino)purin-9-yl]-5-{3-[2-fluorophenyl]prop-2-ynyl}oxolane-3,4-diol;

[0523](4S,2R,3R,5R)-2-[6-(2-fluorocyclohexylmethylamino)purin-9-yl]-5-{3-[2-fluorophenyl]prop-2-ynyl}oxolane-3,4-diol;

[0524](4S,2R,3R,5R)-2-[6-(3-fluorocyclopentylamino)purin-9-yl]-5-{3-[2-fluorophenyl]prop-2-ynyl}oxolane-3,4-diol;

[0525](4S,2R,3R,5R)-2-[6-(4-trifluoromethylcyclopentylamino)purin-9-yl]-5-{3-[2-fluorophenyl]prop-2-ynyl}oxolane-3,4-diol;

[0526](4S,2R,3R,5R)-2-[6-(phenylamino)purin-9-yl]-5-{3-[2-fluorophenyl]prop-2-ynyl}oxolane-3,4-diol;

[0527](4S,2R,3R,5R)-2-[6-(benzylamino)purin-9-yl]-5-{3-[2-fluorophenyl]prop-2-ynyl}oxolane-3,4-diol;

[0528](4S,2R,3R,5R)-2-[6-(pyridin-3-ylamino)purin-9-yl]-5-{3-[2-fluorophenyl]prop-2-ynyl}oxolane-3,4-diol;

[0529](4S,2R,3R,5R)-2-[6-(thiazol-2-ylamino)purin-9-yl]-5-{3-[2-fluorophenyl]prop-2-ynyl}oxolane-3,4-diol;and

[0530](4S,2R,3R,5R)-2-[6-(5-fluorooxolan-3-ylamino)purin-9-yl]-5-{3-[2-fluorophenyl]prop-2-ynyl}oxolane-3,4-diol.

[0531] D. Preparation of a Compound of Formula I Varying R¹, R², R³, R⁴and R⁵, X, X¹ and Y is CH₂, and Z is —C≡C—

[0532] Similarly, following the procedures of Examples 10-16 above,other compounds of Formula I in which X¹ is —CH₂—and Z is —C—C— areprepared.

EXAMPLE 17 Preparation of a Compound of Formula I

[0533] A. Preparation of a Compound of Formula I where R¹ is2-Hydroxycyclopentyl, R² is Hydrogen, R³ is Hydrogen, X, X¹ and Y areCovalent Bonds, and Z is —C≡C—

[0534] 1) To a suspension of potassium t-butoxide (0.84 g, 7.5 mmol) intetrahydrofuran (5 ml) at −78° C. was addedbromomethyltriphenylphosphonium (1.64 g, 3.75 mmol) in small portions,and the mixture stirred for 2 hours. To this mixture was added asolution of(2S,1R,4R,5R)-4-[6-chloropurin-9-yl]-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]octane-2-carbaldehyde(1 mmol) in tetrahydrofuran (20 ml), and the mixture was stirred for 2hours at −78° C. The reaction mixture was then allowed to warm to roomtemperature and stirred for 24 hours, then quenched with aqueousammonium chloride, and partitioned between water and ethyl acetate. Theorganic layer was separated, dried over magnesium sulfate, filtered, andthe solvent removed from the filtrate under reduced pressure, to yield(1R,5R,6R,8R)-6-(6-chloropurin-9-yl)-8-ethynyl-3,3-dimethyl-2,4,7-trioxabicyclo[3.3.0]octane.

[0535] 2) To a solution of(1R,5R,6R,8R)-6-(6-chloropurin-9-yl)-8-ethynyl-3,3-dimethyl-2,4,7-trioxabicyclo[3.3.0]octane(50 mg) and trans 2-aminocyclopentanol (0.04 g) in ethanol was addedtriethylamine (0.12 ml), and the mixture was stirred at 60° C. for 32hours. Solvent was then removed under reduced pressure, and the residuedissolved in ethyl acetate, washed with dilute nitric acid, followed bybrine, dried over sodium sulfate, filtered, and the solvent removed fromthe filtrate under reduced pressure, to provide2-[9-((1R,2R,4R,5R)-4-ethynyl-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]oct-2-yl)purin-6-yl]cyclopentan-1-ol.

[0536] 3) In a sealed tube,2-[9-((1R,2R,4R,5R)-4-ethynyl-7,7-dimethyl-3,6,8-trioxabicyclo[3.3.0]-oct-2-yl)purin-6-yl]cyclopentan-1-olwas stirred in 10 ml of 80% acetic acid/water overnight. The solvent wasthen removed under reduced pressure, and the residue purified bypreparative thin layer chromatography, eluting with 10%methanol/methylene chloride, to provide(4S,2R,3R,5R)-5-ethynyl-2-{6-[(2-hydroxycyclopentyl)amino]purin-9-yl}oxolane-3,4-diol.

[0537] All compounds of Formula I were characterized by nmr spectra andmass spectra. For example:

[0538](4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]-5-ethynyloxolane-3,4-diol:

[0539]¹H-NMR (CDCl₃) 1.54-1.79 (m, 6H), 2.06-2.13 (m, 2H), 3.47 (s, 1H),4.45-4.58 (m, 2H), 4.71 (s, 1H), 4.94 (s, 1H), 6.01 (d, 1H, J=5.09 Hz),6.38 (s, 1H, NH), 8.03 (s, 1H), 8.26 (s, 1H). MH⁺ 317.

[0540](4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]-5-[2-(2-fluorophenyl)ethynyl]oxolane-3,4-diol:

[0541]¹H-NMR (CDCl₃) 1.51-1.77 (m, 6H), 2.08-2.14 (m, 2H), 4.03 (s, 1H,OH), 4.56 (s, 1H, OH), 4.61 (d, 1H, J=4.30 Hz), 4.78-4.81 (m, 1H), 5.21(s, 1H), 5.94 (d, 1H, J=6.65 Hz), 6.07 (d, 1H, J=5.48 Hz), 6.56 (s, 1H,NH), 7.01-7.07 (m, 2H), 7.26-7.35 (m, 2H), 8.11 (s, 1H) MH⁺ 412.

EXAMPLE 18

[0542] Hard gelatin capsules containing the following ingredients areprepared:

[0543] Quantity Ingredient (mg/capsule) Active Ingredient 30.0 Starch305.0 Magnesium stearate 5.0

[0544] The above ingredients are mixed and filled into hard gelatincapsules.

EXAMPLE 19

[0545] A tablet formula is prepared using the ingredients below:

[0546] Quantity Ingredient (mg/tablet) Active Ingredient 25.0 Cellulose,microcrystalline 200.0 Colloidal silicon dioxide 10.0 Stearic acid 5.0

[0547] The components are blended and compressed to form tablets.

EXAMPLE 20

[0548] A dry powder inhaler formulation is prepared containing thefollowing components: Ingredient Weight % Active Ingredient 5 Lactose 95

[0549] The active ingredient is mixed with the lactose and the mixtureis added to a dry powder inhaling appliance.

EXAMPLE 21

[0550] Tablets, each containing 30 mg of active ingredient, are preparedas follows: Quantity Ingredient (mg/tablet) Active Ingredient 30.0 mgStarch 45.0 mg Microcrystalline cellulose 35.0 mg Polyvinylpyrrolidone 4.0 mg (as 10% solution in sterile water) Sodium carboxymethyl starch 4.5 mg Magnesium stearate  0.5 mg Talc  1.0 mg Total  120 mg

[0551] The active ingredient, starch and cellulose are passed through aNo. 20 mesh U.S. sieve and mixed thoroughly. The solution ofpolyvinylpyrrolidone is mixed with the resultant powders, which are thenpassed through a 16 mesh U.S. sieve. The granules so produced are driedat 50° C. to 60° C. and passed through a 16 mesh U.S. sieve. The sodiumcarboxymethyl starch, magnesium stearate, and talc, previously passedthrough a No. 30 mesh U.S. sieve, are then added to the granules which,after mixing, are compressed on a tablet machine to yield tablets eachweighing 120 mg.

EXAMPLE 22

[0552] Suppositories, each containing 25 mg of active ingredient aremade as follows: Ingredient Amount Active Ingredient   25 mg Saturatedfatty acid glycerides to 2,000 mg

[0553] The active ingredient is passed through a No. 60 mesh U.S. sieveand suspended in the saturated fatty acid glycerides previously meltedusing the minimum heat necessary. The mixture is then poured into asuppository mold of nominal 2.0 g capacity and allowed to cool.

EXAMPLE 23

[0554] Suspensions, each containing 50 mg of active ingredient per 5.0mL dose are made as follows: Ingredient Amount Active Ingredient 50.0 mgXanthan gum  4.0 mg Sodium carboxymethyl cellulose (11%)Microcrystalline cellulose (89%) 50.0 mg Sucrose 1.75 g  Sodium benzoate10.0 mg Flavor and Color q.v. Purified water to  5.0 mL

[0555] The active ingredient, sucrose and xanthan gum are blended,passed through a No. 10 mesh U.S. sieve, and then mixed with apreviously made solution of the microcrystalline cellulose and sodiumcarboxymethyl cellulose in water. The sodium benzoate, flavor, and colorare diluted with some of the water and added with stirring. Sufficientwater is then added to produce the required volume.

EXAMPLE 24

[0556] A subcutaneous formulation may be prepared as follows: IngredientQuantity Active Ingredient 5.0 mg Corn Oil 1.0 mL

EXAMPLE 25

[0557] An injectable preparation is prepared having the followingcomposition: Ingredients Amount Active ingredient 2.0 mg/ml Mannitol,USP  50 mg/ml Gluconic acid, USP q.s. (pH 5-6) water (distilled,sterile) q.s. to 1.0 ml Nitrogen Gas, NF q.s.

EXAMPLE 26

[0558] A topical preparation is prepared having the followingcomposition: Ingredients grams Active ingredient 0.2-10 Span 60 2.0Tween 60 2.0 Mineral oil 5.0 Petrolatum 0.10 Methyl paraben 0.15 Propylparaben 0.05 BHA (butylated hydroxy anisole) 0.01 Water q.s. to 100

[0559] All of the above ingredients, except water, are combined andheated to 60° C. with stirring. A sufficient quantity of water at 60° C.is then added with vigorous stirring to emulsify the ingredients, andwater then added q.s. 100 g.

EXAMPLE 27

[0560] Sustained Release Composition Weight Preferred Ingredient Range(%) Range (%) Most Preferred Active ingredient 50-95 70-90 75Microcrystalline cellulose (filler)  1-35  5-15 10.6 Methacrylic acidcopolymer  1-35   5-12.5 10.0 Sodium hydroxide 0.1-1.0 0.2-0.6 0.4Hydroxypropyl methylcellulose 0.5-5.0 1-3 2.0 Magnesium stearate 0.5-5.01-3 2.0

[0561] The sustained release formulations of this invention are preparedas follows: compound and pH-dependent binder and any optional excipientsare intimately mixed(dry-blended). The dry-blended mixture is thengranulated in the presence of an aqueous solution of a strong base whichis sprayed into the blended powder. The granulate is dried, screened,mixed with optional lubricants (such as talc or magnesium stearate), andcompressed into tablets. Preferred aqueous solutions of strong bases aresolutions of alkali metal hydroxides, such as sodium or potassiumhydroxide, for example sodium hydroxide, in water (optionally containingup to 25% of water-miscible solvents such as lower alcohols).

[0562] The resulting tablets may be coated with an optional film-formingagent, for identification, taste-masking purposes and to improve ease ofswallowing. The film forming agent will typically be present in anamount ranging from between 2% and 4% of the tablet weight. Suitablefilm-forming agents are well known to the art and include hydroxypropyl.methylcellulose, cationic methacrylate copolymers (dimethylaminoethylmethacrylate/methyl-butyl methacrylate copolymers—Eudragit® E—Röhm.Pharma), and the like. These film-forming agents may optionally containcolorants, plasticizers, and other supplemental ingredients.

[0563] The compressed tablets have a hardness sufficient to withstand 8Kp compression. The tablet size will depend primarily upon the amount ofcompound in the tablet. The tablets will include from 300 to 1100 mg ofcompound free base. For example, the tablets will include amounts ofcompound free base ranging from 400-600 mg, 650-850 mg, and 900-1100 mg.

[0564] In order to influence the dissolution rate, the time during whichthe compound containing powder is wet mixed is controlled. For examplethe total powder mix time, i.e. the time during which the powder isexposed to sodium hydroxide solution, will range from 1 to 10 minutesand preferably from 2 to 5 minutes. Following granulation, the particlesare removed from the granulator and placed in a fluid bed dryer fordrying at about 60° C.

EXAMPLE 28

[0565] Materials

[0566] The A₁-adenosine antagonists 8-cyclopentyl-1,3-dipropylxanthine(CPX) and 8-cyclopentyl-1,3-dimethylxanthine (CPT), the A₁-adenosineagonists N₆-cyclopentyladenosine (CPA), 2-chloro-N₆-cyclopentyladenosine(CCPA), and —N₆-cyclohexyladenosine (CHA), the adenosine deaminaseinhibitor erythro-9-(2-hydroxy-3-nonyl)adenine (EHNA), the adenosinekinase inhibitor iodotubercidin, and forskolin were purchased fromResearch Biochemicals (Natick, Mass.).{[(5-{6-[(3R)oxolan-3-yl]amino}purin-9-yl)(3S,2R,4R)-3,4-di-hydroxyoxolan-2-yl]-methoxy}-N-methylcarboxamide, molecular weight 394.38, is a derivative of theselective A₁-adenosine receptor full agonist CVT-510. Adenosine waspurchased from Sigma Chemical (St. Louis, Mo.). The radioligand8-cyclopentyl-1,3-dipropyl-[2,3-³H(N)]xanthine ([³H]CPX) was purchasedfrom New England Nuclear (Boston, Mass.). Concentrated stock solutions(10-100 mM) of CVT-2759, CPX, CPT, CPA, CCPA, CHA, and forskolin weredissolved in dimethylsulfoxide, stored as aliquots at −80° C., anddiluted in physiological saline for use in experiments. The finalcontent of dimethylsulfoxide in saline during experiments was not morethan 0.1%. Adenosine and EHNA were dissolved in saline immediatelybefore use.

Binding Assays—DDT₁ Cells

[0567] Cell Culture

[0568] DDT cells (hamster vas deferens smooth muscle cell line) weregrown as monolayers in petri dishes using Dulbecco's Modified Eagle'sMedium (DMEM) containing 2.5 μg ml⁻¹ amphotericin B, 100 U ml⁻¹penicillin G, 0.1 mg ml⁻¹ streptomycin sulfate and 5% fetal bovine serumin a humidified atmosphere of 95% air and 5% CO₂. Cells were subculturedtwice weekly by dispersion in Hank's Balanced Salt Solution (HBSS)without the divalent cations and containing 1 mM EDTA. The cells werethen seeded in growth medium at a density of 1.2×10⁵ cells per plate andexperiments were performed 4 days later at approximately one daypreconfluence.

[0569] Membrane Preparations

[0570] Cell layers were washed twice with HBSS (2×10 ml), scraped freeof the plate with the aid of a rubber policeman in 5 ml of 50 mMTris-HCl buffer pH 7.4 at 4° C. and the suspension homogenized for 10 s.The homogenate was centrifuged at 27,000× g for 10 min, resuspended inbuffer, and centrifuged again, as described above. The protein contentwas determined with a Biorad Protein Assay Kit (Richmond, Calif.) usingbovine serum albumin as standard. This membrane suspension was storeddimethylsulfoxide (DMSO) in He buffer (10 mM HEPES, 1 uM EDTA at pH 7.4)and stored in liquid nitrogen at −80° C.

[0571] Competitive Binding Assays:

[0572] Compounds of Formula I were assayed to determine their affinityfor the A₁ adenosine receptor sites on the membranes of DDT cells.Briefly, 50-70 ug of membrane protein were incubated in a mixturecontaining 2U/ml adenosine deaminase, 10 mM GTP-γS in 5 mM HE buffercontaining 5MM MgCl₂ in glass tubes. Stock solutions of the compounds ofthe invention were serially diluted (10-¹⁰M to 10⁻⁴M) in HE buffer or HEbuffer alone (control to determine non-specific binding) and added tothe incubation mixture. Finally, tritiated cyclopentyladenosine (³H—CPA)was added to a final concentration of 1.5 nM. After incubation at 23° C.90 minutes, the reaction was stopped by filtration on a Brandel MR24cell harvester and washing with ice-cold Tris-EDTA buffer (three times,approximate volume 10 ml/wash) over Whatman GF/B filters (presoaked for1 h in 0.3% polyethylenimine to reduce non-specific binding). Filterswere transferred to scintillation vials and 5 ml of Scintisafe (VWR,Brisbane, Calif.) was added. The amount of radioactivity retained on thefilters was determined by liquid scintillation spectrometry. Proteindeterminations were by the method of Bradford (1976. Anal. Biochem.72:248) using bovine serum albumin as the standard.

[0573] The compounds of Formula I were shown to be Al-adenosine receptoragonists in this assay.

EXAMPLE 29 [³⁵S]GTPγS Binding Assays

[0574] The ability of agonists to activate G proteins was determined byusing radiolabeled GTP ([³⁵S]GTPγS). Briefly, membrane proteins (30-50μg/assay tube) were placed in glass tubes containing 50 mM Tris-HClbuffer pH 7.4, 5 mM MgCl₂, 100 mM NaCl, 1 mM dithiothreitol, 0.2 unitsml⁻¹ adenosine deaminase, 0.5% BSA, 1 mM EDTA, 10 mM GDP, and 0.3 nM[³⁵S]GTPγS. Varying concentrations of the compounds of the invention(putative A₁ adenosine receptor agonists), a known A₁ adenosine receptorfull agonist N cyclopentlyladenosine (CPA or CCPA) or a control tubecontaining 10 μM GTPγS but no agonist (to determine nonspecific binding)were added to separate tubes. The assay tubes were incubated for 90minutes at 37° C. Agonist stimulated binding was assessed by determiningthe difference between total binding in the presence of putativeagonists and basal binding determined in the absence of CPA. Resultswere expressed as the percentage stimulation of the putative agonistsrelative to the full agonist CPA after subtracting out non-specificbinding.

[0575] The compounds of Formula I were shown to be A₁-adenosine receptoragonists in this assay.

EXAMPLE 30

[0576] Guinea Pig Isolated Perfused Hearts

[0577] Guinea pigs (Hartley) of either sex weighing 300-350 g areanaesthetized with methoxyflurane and killed by decapitation. The chestis cut open, and the heart quickly removed and rinsed in ice-coldmodified Krebs-Henseleit (K-H) solution. The contents of the modifiedK-H solution are (in mM) 117.9 NaCl, 4.8 KCl, 2.5 CaCl₂, 1.18 MgSO₂, 1.2KH₂P0₄, 0.5 Na₂ EDTA, 0.14 ascorbic acid, 5.5 dextrose, 2.0 pyruvic acid(sodium salt), and 25 NaHCO₃. The K-H solution is continuously gassedwith 95% 0₂-5% C0₂, and the pH adjusted to a value of 7.4. To perfusethe heart by the Langendorff method, the transected aorta is put onto aglass cannula and secured by a ligature. Retrograde perfusion of theaorta is initiated immediately at a constant flow of 10 ml/min withmodified K-H solution warmed to 36.0±0.5° C. A side port in the cannulais used to connect the perfusion line to a Gould pressure transducer formeasurement of coronary perfusion pressure. Coronary perfusion pressurewas continuously recorded on a strip chart (Gould RS3400, Cleveland,Ohio) throughout each experiment. Coronary conductance (inml.min⁻¹.mmHg-1) is calculated as the ratio of coronary flow (10 ml/min)to perfusion pressure (in mmHg). To facilitate the exit of fluid fromthe left ventricle, the leaflets of the mitral valve are trimmed withfine spring-handled scissors. When appropriate, hearts are paced at aconstant rate using external electrodes. After completion of dissectionand instrumentation, stimulus-to-His bundle (S-H) interval and coronaryperfusion pressure is monitored continuously, each heart being allowedto equilibrate for 20-40 min before the administration of drug.Experimental interventions are always preceded and followed by controlmeasurements. Criteria for the exclusion of hearts from the study are 1)a coronary perfusion pressure of <50 mmHg, 2) absence of a stablecoronary perfusion pressure during the equilibration period, and 3)inability to pace a heart at a constant rate throughout an experiment.

[0578] For electrical pacing of hearts, a bipolar Teflon-coatedelectrode is placed in the wall of the intra-atrial septum. Parts of theleft and right atrial tissues, including the region of the sinoatrialnode, are removed, both to decrease the spontaneous heart rate and toexpose the atrial septum for electrode placement. Hearts areelectrically paced at a fixed rate of 3.2 HZ. Stimuli are provided by aninterval generator (model 1830, WPI, Sarasota, Fla.) and deliveredthrough a stimulus isolation unit (model 1880, WPI) as square wavepulses of 3 ms in duration and at least twice the threshold intensity.

[0579] S-H interval Prolongation of the S-H interval is used as ameasure of the negative dromotropic effect of A₁-adenosine agonists onAV nodal conduction. The His bundle electrogram is recorded from aunipolar electrode placed in the right side of the interatrial septumadjacent to the AV junction. The signal is displayed continuously inreal time on an oscilloscope screen at a sweep rate of 10 ms/cm. Theduration of time from the first pacing artifact to the maximum upwarddeflection of the His bundle signal is used as the S-H interval.

[0580] Hearts are equilibrated until the S-H interval and CPP remainsconstant. The test compound is used to the perfused line in a finalconcentration of 0.3, 3, 10 and in some hearts up to 30 μM. If thesecond degree AV block happens at any concentration before 30 μM, thetest compound is withdrawn to washout. After washout of the first testcompound, a second test compound could not be used in the same heartunless the SH interval and CPP comes back to the control or S-H intervalis prolonged less than 2 ms compared to the control. Up to threecompounds can be used in the same heart.

[0581] The compounds of Formula I demonstrate the ability to delay AVnodal conduction in this assay.

EXAMPLE 31

[0582] Anti-Emesis Studies

[0583] For all the experiments adult male ferrets, body weight range1-1.5 kg, are used. Emesis is induced by X-irradiation, morphine andcisplatin.

[0584] X-irradiation:

[0585] The ferrets are weighed on the day before the experiment. On theday of the experiment each ferret receives 2Gy (20ORad) whole bodyX-irradiation, administered over a 5 minute period. The A₁ receptoragonists or partial agonists are administered via the subcutaneous routeimmediately after X-irradiation(i.e. approximately 25 minutes before theonset of emesis). When investigating the effects of the A₁ receptorantagonist, DPCPX, on the partial agonist either both compounds areadministered simultaneously immediately after X-irradiation, or theDPCPX was given as a 15 minute pre-treatment. In all cases, the ferretsare observed for 2 hours after X-irradiation, and the time and numbersof retches and vomits are recorded.

[0586] Morphine:

[0587] The ferrets are weighed on the day before the experiment. Theadenosine A₁ receptor agonist is administered subcutaneously 15 minutesbefore the 0.5 mg kg-1 subcutaneous dose of morphine. (Emesis normallystarts 5 minutes after morphine administration). The ferrets areobserved for 2 hours after the morphine dose and the time and numbers ofretches and vomits are recorded.

[0588] Cisplatin:

[0589] The ferrets are weighed and measured for the calculation of bodysurface area on the day before the experiment. On the day of theexperiment each ferret receives an intraperitoneal dose of cisplatin(200 mg m-2). The adenosine A₁ receptor agonist is administeredsubcutaneously immediately after the first emetic episode (approximately1.5 hours after cisplatin administration). The ferrets are observed for7 hours after the first emetic episode and the time and numbers ofretches and vomits are recorded.

[0590] The compounds of Formula I demonstrate the ability to controlemesis in this assay.

DETERMINATION OF ANTILIPOLYITIC PROPERTIES

[0591] Animals.

[0592] Male Sprague-Dawley rats (380-420 g) were purchased from SimonsenLaboratories (Gilroy, Calif.). All animals received humane careaccording to the guidelines set forth in The Principles of LaboratoryAnimal Care formulated by the National Society for Medical Research andthe Guide for the Care and Use of Laboratory Animals prepared by theInstitute of Laboratory Animal Resources and published by the NationalInstitute of Health (NIH Publication 86-23, revised 1996).

[0593] Isolation of Rat Epididymal Adipocytes.

[0594] Adipocytes were isolated from the epididymal fat pads of rats asdescribed previously (Rodbell, 1964). Briefly, rats were anesthetizedusing methoxyfluorane and killed by exsanguination. Epididymal fattissue was removed and placed into a modified Krebs (KRH) solutioncontaining NaCl (100 mM), KCl (4.7 mM), CaCl2 (2.5 mM), NaHCO3 (3.6 mM),MgSO4 (1.19 mM), KH2PO4 (1.18 mM), dextrose (5 mM), pyruvic acid (5 mM),ascorbic acid (1 mM), and HEPES (5 mM), pH 7.4. Visible blood vesselswere dissected and excised, and the adipose tissue was minced. Mincedtissue was digested with 25 ml of fresh KRH solution containing type Icollagenase (1 mg/ml), fatty-acid free BSA [1% (wt/vol)]and nicotinicacid (2_M, to inhibit lipolysis) for 40 to 60 minutes at 37° C. withcontinuous gentle shaking. The cell suspension was filtered through anylon-mesh (210_m) to remove undigested tissue fragments. The cellfiltrate was washed three times using KRH solution containing 1% fattyacid-free BSA at 37° C. The final adipocyte suspension was eitherdiluted in fresh KRH solution with 1% fatty acid-free BSA for use incAMP experiments, or used to prepare membranes for radioligand bindingassays.

[0595] cAMP Assays in Isolated Rat Adipocytes.

[0596] Aliquots (100 μl, 45,000-90,000 cells) of the freshly preparedadipocyte cell suspension were placed into wells of 24-well cell cultureplates containing 0.4 ml of KRH solution containing fatty acid-free BSA(1%), ascorbic acid (1 mM), rolipram (10 μM), cilostamide (1 μM),adenosine deaminase (2 U/ml), and appropriate A₁ adenosine receptoragonist(s). An aliquot of 0.5 ml of KRH solution containing 60 nMisoproterenol was added to each well, and incubations proceeded for 4min in an orbital shaker bath maintained at 37° C. Assays wereterminated by the addition of 200 μl of 300 mM HCl to each well to lysethe cells. The concentration of cAMP in the cell lysate was determinedusing colorimetric direct cAMP kits (Assay Designs, Inc., Ann Arbor,Mich.).

[0597] Adipocyte Membrane Preparation and Competition Binding

[0598] Assays.

[0599] Freshly isolated adipocytes were added to a chilled solutioncontaining sucrose (0.25 M), EDTA (1 mM), and Tris-HCl (10 mM, pH 7.4)and homogenized with 10 strokes using a motordriven tissue grinder. Thehomogenate was cooled on ice and the fat layer was discarded. Thehomogenate was then centrifuged at 500 g for 10 min at 4° C. Thesupernatant under the fat layer was removed, resuspended in freshbuffer, and homogenized a second time with six strokes using the tissuegrinder. Cell membranes were collected by centrifugation of thehomogenate at 15,000 g for 15 min. The final membrane pellet wasresuspended in a solution containing sucrose (0.25 M),phenylmethylsulfonyl fluoride (0.1 mM), leupeptin (5 μg/ml), aprotinin(5 g/ml), adenosine deaminase (2 U/ml), and Tris-HCl (10 mM) buffer, pH7.4. The membrane suspension was frozen and stored in liquid nitrogen.For competition binding assays, membrane suspensions were thawed andincubated for 2 hours at room temperature in Tris-HCl (50 mM) buffercontaining ADA (1 U/ml), guanosine 5-(imido)triphosphate (100M), and[3H]CPX (1-3nM) and progressively higher concentrations of the competingagent. At the end of incubation, free radioligand was separated frommembrane-bound radioligand by filtration through GF/C glass fiberfilters (Whatman, Maidstone, UK) using a tissue harvester (Brandel,Inc., Gaithersburg, Md.). Radioactivity was quantified by liquidscintillation counting. Nonspecific binding of [3H]CPX was defined as[3H]CPX bound in the presence of 10 μMN6-cyclopentyltheophylline.Triplicate determinations were performed for each concentration ofunlabeled compounds.

[0600] Effects of Compounds of Formula I on Heart Rate and Serum NEFAConcentration in Awake Rats.

[0601] Heart rate was measured from rats chronically instrumented withtelemetry transmitters. For transmitter implantation, a midlinelaparotomy was performed on anesthetized rats and a transmitter for ECGrecording was sutured to the abdominal wall. The twoelectrocardiographic leads were tunneled through the wall, passedsubcutaneously (one to the left shoulder, the other to the right thigh),and secured in place with sutures. Heart rates of awake rats weremeasured using a Dataquest ART Gold System (Data Sciences International,St. Paul, Minn.). Cardiac electrical activity was recorded for 10-speriods and used to calculate heart rate in beats per minute. Afterrecording of a baseline heart rate, either vehicle (0.9% DMSO in saline,0.5 ml) or a compound of Formula I was injected into the intraperitonealcavity of each rat, and heart rate was monitored at intervals for anadditional 3 hours.

[0602] The effects of a compound of Formula I on heart rate and serumNEFA reduction concentration were determined in separate groups of ratsto avoid the effects of animal handling and blood sampling on heartrate. Three days before an experiment, a catheter (0.025-mm outerdiameter) was implanted in the left common carotid artery of each ratusing aseptic conditions and sterile technique. The catheter wastunneled subcutaneously to the dorsal surface. After recovery fromanesthesia, rats were placed in metabolic cages to facilitate handlingand blood sampling. Blood samples (0.2 ml) were drawn before and atvarious time points after i.p. injection of either a compound of FormulaI or vehicle (DMSO in saline). A 0.4-ml volume of 1% sodium citrate insaline was administered after withdrawal of each blood sample to replaceblood volume and prevent clotting in the carotid artery catheter. Serumwas collected from each sample after centrifugation of the clottedblood. Serum samples were stored at _(—)80° C. until analysis. SerumNEFA concentration was determined using an enzymatic colorimetric assaykit (Wako Chemicals, Richmond, Va.).

[0603] The antilipolytic properties of compounds of Formula I in ratswith catecholamines- stimulated NEFA levels were studied in rats withindwelling catheters (described above). Norepinephrine was deliveredeither by i.v. infusion into the jugular vein at 3 μg/kg/min for 30minutes or by i.p. injection (60 μg/kg). A compound of Formula I wasdelivered by i.p. injection either before or after norepinephrine todetermine whether the increase in NEFA concentrations caused bynorepinephrine could be prevented or reversed by the compound of FormulaI.

[0604] The compounds of Formula I demonstrated antilipolytic propertiesin this assay. For example, oral administration of(4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]-5-{2-[2-fluorophenyl]-ethynyl}oxolane-3,4-diolat a dose level of 1 mg/Kg provided an initial 40% reduction ofnon-esterified free fatty acid (NEFA) that was maintained for 1 hour,after which time the plasma levels of NEFA returned to normal in 2hours. Oral administration of(4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]-5-{2-[2-fluorophenyl]-ethynyl}oxolane-3,4-diolat a dose level of 2.5 mg/Kg provided an initial 60% reduction ofnon-esterified free fatty acid (NEFA) that was maintained for 90minutes, after which time the plasma levels of NEFA returned to normalin 4 hours.

[0605] At dose levels of 1 mg/kg, 2.5 mg/kg, and 5 mg/kg, no effect onheart rate was observed.

What is claimed is:
 1. A compound of the formula:

wherein: R¹ is optionally substituted cycloalkyl, optionally substitutedheterocyclyl, optionally substituted aryl, or optionally substitutedheteroaryl; R² is hydrogen, halo, trifluoromethyl, or cyano; R³ ishydrogen, optionally substituted cycloalkyl, optionally substitutedaryl, optionally substituted heteroaryl, or optionally substitutedheterocyclyl, R⁴ and R⁵ are independently hydrogen or optionallysubstituted acyl; X is a covalent bond or lower alkylene optionallysubstituted by cycloalkyl; X¹ is a covalent bond or alkylene. Y is acovalent bond or lower alkylene optionally substituted by hydroxy orcycloalkyl; and Z is —C≡C—, —R⁶C═CR⁷—, or —CHR⁶CHR⁷—, in which R⁶ and R⁷at each occurrence are hydrogen or lower alkyl.
 2. The compound of claim1, wherein Z is —C≡C—.
 3. The compound of claim 2, wherein X, X¹ and Yare covalent bonds.
 4. The compound of claim 3, wherein R¹ is optionallysubstituted cycloalkyl, optionally substituted heterocyclyl, oroptionally substituted heteroaryl.
 5. The compound of claim 4, whereinR², R⁴ and R⁵ are hydrogen.
 6. The compound of claim 5, wherein R³ ishydrogen or optionally substituted aryl.
 7. The compound of claim 6,wherein R¹ is optionally substituted cyclopentyl or optionallysubstituted tetrahydrofuranyl and R³ is hydrogen or optionallysubstituted phenyl.
 8. The compound of claim 7, wherein R¹ iscyclopentyl and R³ is hydrogen, namely(4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]-5-ethynyloxolane-3,4-diol.9. The compound of claim 7, wherein R¹ is 2-hydroxycyclopentyl and R³ ishydrogen, namely(4S,2R,3R,5R)-5-ethynyl-2-{6-[(2-hydroxycyclopentyl)amino]purin-9-yl}oxolane-3,4-diol.10. The compound of claim 7, wherein R¹ is tetrahydrofuran-3-yl and R³is hydrogen, namely(4S,2R,3R,5R)-2-[6-(oxolan-3-ylamino)purin-9-yl]-5-ethynyloxolane-3,4-diol.11. The compound of claim 7, wherein R¹ is cyclopentyl and R³ is2-fluorophenyl, namely(4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]-5-[2-(2-fluorophenyl)ethynyl]oxolane-3,4-diol.12. The compound of claim 7, wherein R¹ is cyclopentyl and R³ is2-trifluoromethylphenyl, namely(4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]-5-{2-[2-(trifluoromethyl)-phenyl]ethynyl}oxolane-3,4-diol.13. The compound of claim 7, wherein R¹ is tetrahydrofuran-3-yl and R³is 2-fluorophenyl, namely(4S,2R,3R,5R)-2-[6-(oxalan-3-ylamino)purin-9-yl]-5-{2-[2-fluorophenyl]ethynyl}oxolane-3,4-diol.14. The compound of claim 7, wherein R¹ is tetrahydrofuran-3-yl and R³is 2-trifluoromethylphenyl, namely(4S,2R,3R,5R)-2-[6-(oxalan-3-ylamino)purin-9-yl]-5-{2-[2-(trifluoromethyl)phenyl]-ethynyl}oxolane-3,4-diol.15. The compound of claim 5, wherein R³ is optionally substitutedheteroaryl.
 16. The compound of claim 15, wherein R¹ is optionallysubstituted cyclopentyl or optionally substituted tetrahydrofuranyl andR³ is optionally substituted thienyl.
 17. The compound of claim 16,wherein R¹ is cyclopentyl or tetrahydrofuran-3-yl and R³ is thien-2-yl.18. The compound of claim 1, wherein Z is —R⁶C═CR⁷—, in which R⁶ and R⁷are both hydrogen.
 19. The compound of claim 18, wherein X, X¹ and Y arecovalent bonds.
 20. The compound of claim 19, wherein R¹ is optionallysubstituted cycloalkyl.
 21. The compound of claim 20, wherein R², R⁴ andR⁵ are hydrogen.
 22. The compound of claim 21, wherein R³ is optionallysubstituted aryl or optionally substituted heteroaryl.
 23. The compoundof claim 22, wherein R¹ is cyclopentyl and R³ is 5-chlorothien-2-yl,4-methylisoxazol-3-yl or 3,5-dimethylisoxazol-4-yl.
 24. The compound ofclaim 22, wherein R¹ is cyclopentyl and R³ is 2-methyphenyl, namely5-[2-(2-methylphenyl)vinyl](4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]oxolane-3,4-diol.25. The compound of claim 22, wherein R¹ is cyclopentyl and R³ isphenyl, namely5-[2-(phenyl)vinyl](4S,2R,3R,5R)-2-[6-(cyclopentylamino)purin-9-yl]oxolane-3,4-diol.26. A method of treating a disease state in a mammal by administrationof an A₁ adenosine receptor agonist, comprising administering to amammal in need thereof a therapeutically effective dose of a compound ofclaim
 1. 27. The method of claim 26, wherein the disease state is chosenfrom atrial fibrillation, supraventricular tachycardia and atrialflutter, congestive heart failure, epilepsy, stroke, diabetes, obesity,ischemia, stable angina, unstable angina, cardiac transplant, andmyocardial infarction.
 28. The method of claim 27, wherein the diseasestate is chosen from atrial fibrillation, supraventricular tachycardiaand atrial flutter.
 29. The method of claim 26, wherein the A₁ adenosinereceptor agonist of claim 1 has an antilipolytic effect.
 30. The methodof claim 29, wherein said antilipolytic effect treats disease statesrelated to metabolic disorders
 31. The method of claim 30, wherein themetabolic disorder is hyperlipidemia, non-insulin-dependent diabetesmellitus, or obesity.
 32. A pharmaceutical composition comprising atleast one pharmaceutically acceptable excipient and a therapeuticallyeffective amount of a compound of Formula I.